Code of Conduct
Page 1 of 4 1 2 3 4 LastLast
Results 1 to 60 of 221

Thread: Schiff's bases

  1. #1

    Default Schiff's bases

    And another one -
    Is this a right way to think about Schiff's bases - if I like an aldehyde, and want
    something similar as a base (i.e - long lived), I should just add the same amount
    of methyl anthranilate (or indole..)?

  2. #2

    Default Re: Schiff's bases

    NO!! A Schiff's Base is the reaction product between an ALdehyde and a compound containing an animo group (NH2); often, in Perfumery this is Methyl Anthranilate. A Schiff's Base is already reacted. When you mix the Aldehyde and Amino Group material, you produce the Schiff's Base and water. When you add an aldehyde plus Methyl Anthranilate to your perfume, you can produce all sorts of reaction products; and water. You don't want that, as it is uncontrolled.

  3. #3

    Default Re: Schiff's bases

    Bummer.. I was hoping that could be a way to fix some of my favorite aldehydes..
    And there aren't that many Schiff's bases being sold (in small quantities..) Thanks!

  4. #4

    Default Re: Schiff's bases

    You can do that! Just don't do it in your perfume and expect consistent controllable results, especially if you have a bunch of different aldehydes. Do it in a separate reaction container with a dessicant to absorb the water (this will also push the reaction forwards). You have to add 1:1 molar quantities, not 1:1 weight quantities. That means you want one molecule of the aldehyde for every molecule of the methyl anthranilate. You can find this out by looking up the molecular weights of the compounds, and using those to determine the right ratios. If it gives you trouble shoot me a PM and I'll walk you through an example.

    Try to stir the mixtures, or if not possible, shake/swirl every now and then, and keep a watch glass or other loose lid over the top. It may take hours to go anywhere much. Don't expect instant spectacular results like you'd get mixing baking soda and vinegar. There will likely be a color change. Eventually you should wind up with your own custom Schiff's base. If it's possible to predict the smell, I have no idea. I've heard the notion that a Schiff's base returns to its original components in the nose, and you then smell it the same as the unreacted mixture, but that doesn't seem to hold completely true judging by the single one I've smelled so far.

    It sounds like a lot of fun. I'm planning on doing it myself after I get done synthesizing a couple ketones I can't get my hands on in small quantities.

  5. #5

    Default Re: Schiff's bases

    It does sound like fun. How do you absorb the water exactly?
    It might not be a problem if I use a few % of this base in the concrete (I guess?). Will this also work with indole? I still dont have MA..
    It's weird that I couldn't find a comprehensive review of those bases..

  6. #6
    Basenotes Plus

    Join Date
    Jul 2013
    Location
    Portland, Oregon
    Posts
    687

    Default Re: Schiff's bases

    Quote Originally Posted by Nizan View Post
    It does sound like fun. How do you absorb the water exactly?
    It might not be a problem if I use a few % of this base in the concrete (I guess?). Will this also work with indole? I still dont have MA..
    It's weird that I couldn't find a comprehensive review of those bases..
    I've experimented and made a few. I measure out my ingredients and put them into borosilicate glass and heat them on a hot plate, carefully monitoring temps and making sure the solution doesn't boil. For the three I've made the mixture turns dark yellow and the water separates and forms a distinct line on top of the solution. I pour mine through a desiccant, if you don't have a desiccant you can let it settle and pipette the water off the top. The resulting base is insanely strong, when I get it on my hands it doesn't wash off with repeated soapings and takes up to a day or more to go away. I find the smell to be very similar to the combination of ingredients, to me it doesn't end up smelling novel so much as just smelling stronger for longer. After aging the edges soften and it becomes more well blended but it still smells like a combination of it's constituents mostly. There are some differences in the final solution but they are subtle to me, perhaps not to someone else.
    Justin E. Beasley

  7. #7

    Default Re: Schiff's bases

    I use 3A molecular sieves because I'm used to them, but I'm usually working with water-thin liquids and there are other driers out there that would probably work just as well. Otherwise, you should be able to gently heat the water out of the end product since the Schiff's base should have a significantly higher boiling point than water, but it might take a long while to clear up. Vigon evidently removes the water under vacuum. I'd like to try that myself but I don't have a vacuum pump at home yet. The note about high viscosity is something I hadn't considered. Some of the end products might be very thick and require a solvent (or higher temperature) to make things workable.

    It should work with indole as well, as far as I know. Indolene 50 is a Schiff's base from indole and hydroxycitronellal.
    Last edited by JayH; 14th February 2014 at 03:32 AM. Reason: incorrect information

  8. #8

    Default Re: Schiff's bases

    Quote Originally Posted by JEBeasley View Post
    There are some differences in the final solution but they are subtle to me, perhaps not to someone else.
    My mind's probably playing tricks on me then. I need to go sniff Indolene 50 again. That's interesting that your water separated out. It's exactly what I would hope for but you're the first I've seen making perfumery Schiff's bases who hasn't referenced a cloudy mixture as the result. I wonder if heating helped with that.

    I just got a bunch of borosilicate test tubes, too. I think I'm going to go wreck a few in the spirit of curiosity.

  9. #9
    Basenotes Plus

    Join Date
    Jul 2013
    Location
    Portland, Oregon
    Posts
    687

    Default Re: Schiff's bases

    Quote Originally Posted by JayH View Post
    I use 3A molecular sieves because I'm used to them, but I'm usually working with water-thin liquids and there are other driers out there that would probably work just as well. Otherwise, you should be able to gently heat the water out of the end product since the Schiff's base should have a significantly higher boiling point than water, but it might take a long while to clear up. Vigon evidently removes the water under vacuum. I'd like to try that myself but I don't have a vacuum pump at home yet. The note about high viscosity is something I hadn't considered. Some of the end products might be very thick and require a solvent (or higher temperature) to make things workable.

    It should work with indole as well, as far as I know. Indolene 50 is a Schiff's base from indole and hydroxycitronellal.
    I use Anhydrous Sodium Sulfate as a desiccant. I make the schiff base and just mix in some sodium sulfate, shake it, let it sit and then filter it out with a coffee filter in a glass funnel. When I was trying to oxidize a C11 schiff base I boiled it intentionally, the water did cook off and the resulting solution clarified nicely.
    Last edited by JEBeasley; 26th January 2014 at 09:25 PM.
    Justin E. Beasley

  10. #10
    Basenotes Plus

    Join Date
    Jul 2013
    Location
    Portland, Oregon
    Posts
    687

    Default Re: Schiff's bases

    Quote Originally Posted by JayH View Post
    My mind's probably playing tricks on me then. I need to go sniff Indolene 50 again. That's interesting that your water separated out. It's exactly what I would hope for but you're the first I've seen making perfumery Schiff's bases who hasn't referenced a cloudy mixture as the result. I wonder if heating helped with that.

    I just got a bunch of borosilicate test tubes, too. I think I'm going to go wreck a few in the spirit of curiosity.
    I have Indolene 50 and like it a lot more than straight indole, it's softer and less intense.

    You won't wreck your test tubes, they're made for this. The schiff base will wash out well enough with a good tube brush and dish detergent. If it has some smell left over you can run them through the dishwasher or ultrasonic cleaner and some solvent.

    I've only made the schiff bases by cooking them and the three I've made turned out clear as a bell... and yellow. Maybe some others turn another color, I don't know. I think that if you oxidize the schiff base you can change the smell a little more.
    Last edited by JEBeasley; 26th January 2014 at 09:22 PM.
    Justin E. Beasley

  11. #11

    Default Re: Schiff's bases

    Quote Originally Posted by JEBeasley View Post
    I've only made the schiff bases by cooking them and the three I've made turned out clear as a bell... and yellow. Maybe some others turn another color, I don't know. I think that if you oxidize the schiff base you can change the smell a little more.
    Interesting JEBeasley, which one have you made?
    Paul Kiler
    PK Perfumes
    http://www.PKPERFUMES.com
    Gold Medal for "Best Aroma"; Los Angeles Artisan Fragrance Salon

  12. #12

    Default Re: Schiff's bases

    Quote Originally Posted by JEBeasley View Post
    You won't wreck your test tubes, they're made for this.
    I was joking. I'm not intending to deliberately wreck them, just acknowledging the possibility.

  13. #13
    Basenotes Plus

    Join Date
    Jul 2013
    Location
    Portland, Oregon
    Posts
    687

    Default Re: Schiff's bases

    C11 + methyl anthranilate
    C12 MNA + methyl anthranilate
    C16 + methyl anthranilate

    The C16 base... Everything I've made with it ends up smelling like a cheesy head-shop incense. It's so strong and artificial strawberry, I need to learn moderation with it So far my experiences have turned me off from it but eventually I'll revisit when I've gained some perspective and can handle the smell being in my nose for several days. When I heat them on the hotplate the smell permeates the air.

    My reference to oxidization came from the article that was posted here a while back I think, maybe it was on the yahoo perfumery forum. It was in regards to oxidization of C11 and it's use to reinforce olibanum as a base, I remember reading the patent and what I got from it was that the use of the oxidized form within a perfume was patented by one of the big perfume companies. I'm not discounting the idea that I might have misread, misunderstood or misremember though.
    Last edited by JEBeasley; 26th January 2014 at 11:44 PM.
    Justin E. Beasley

  14. #14

    Default Re: Schiff's bases

    Probably the C12 MNA to reinforce Frankincense...
    Paul Kiler
    PK Perfumes
    http://www.PKPERFUMES.com
    Gold Medal for "Best Aroma"; Los Angeles Artisan Fragrance Salon

  15. #15

    Default Re: Schiff's bases

    How did the C12MNA come out smelling? Was it like MNA but with a floral undertone? If I had the proper expertise and equipment, I would love to try anisaldehyde or Triplal with methyl anthranilate.

  16. #16

    Default Re: Schiff's bases

    Quote Originally Posted by JEBeasley View Post
    C11 + methyl anthranilate
    C12 MNA + methyl anthranilate
    C16 + methyl anthranilate

    The C16 base... Everything I've made with it ends up smelling like a cheesy head-shop incense. It's so strong and artificial strawberry, I need to learn moderation with it So far my experiences have turned me off from it but eventually I'll revisit when I've gained some perspective and can handle the smell being in my nose for several days. When I heat them on the hotplate the smell permeates the air.

    My reference to oxidization came from the article that was posted here a while back I think, maybe it was on the yahoo perfumery forum. It was in regards to oxidization of C11 and it's use to reinforce olibanum as a base, I remember reading the patent and what I got from it was that the use of the oxidized form within a perfume was patented by one of the big perfume companies. I'm not discounting the idea that I might have misread, misunderstood or misremember though.
    "Aldehyde" C16 isn't an aldehyde, it is an Ester, so will not make a Schiff's Base with Methyl Anthranilate.
    The oxidation product of Aldehyde C11 would be the corresponding Acid.

    I'm very surprised that some folk have been able to filter their Schiff's Bases; in my experience they are far to viscous for this to happen. Adding Anhydrous Sodium Sulphate will make it even thicker, and less able to be filtered. To remove water in this way, once the reaction has completed it would be necessary to dilute the Schiff's Base and then add Sodium Sulphate and filter. It could be that the reaction has not been allowed to go to completion. Methyl Anthranilate and the various Aldehydes used, are liquid enough to be filtered, the resulting Schiff's Base is not.

    It is often the case that a Schiff's Base with water present, when warmed, will be clear, but allowed to cool down will become cloudy once more. The water is more soluble in warm Schiff's Base.

  17. #17
    Basenotes Plus

    Join Date
    Jul 2013
    Location
    Portland, Oregon
    Posts
    687

    Default Re: Schiff's bases

    Quote Originally Posted by David Ruskin View Post
    "Aldehyde" C16 isn't an aldehyde, it is an Ester, so will not make a Schiff's Base with Methyl Anthranilate.
    The oxidation product of Aldehyde C11 would be the corresponding Acid.

    I'm very surprised that some folk have been able to filter their Schiff's Bases; in my experience they are far to viscous for this to happen. Adding Anhydrous Sodium Sulphate will make it even thicker, and less able to be filtered. To remove water in this way, once the reaction has completed it would be necessary to dilute the Schiff's Base and then add Sodium Sulphate and filter. It could be that the reaction has not been allowed to go to completion. Methyl Anthranilate and the various Aldehydes used, are liquid enough to be filtered, the resulting Schiff's Base is not.

    It is often the case that a Schiff's Base with water present, when warmed, will be clear, but allowed to cool down will become cloudy once more. The water is more soluble in warm Schiff's Base.
    Ok, so the C16 was just an amalgam, now I feel silly. I think I've made this mistake previously, someday I'll learn.

    Sorry, I'm not a chemist, I found some instructions somewhere online, probably somewhere being HERE and assumed C16, being called an aldehyde, was one. I seem to remember one of those didn't change color much through the experiment so it was probably the C16. Oddly enough after the experiment it seemed "stronger" but it was probably my imagination combined with expectation and the fact that I cooked it into my sinuses and couldn't smell much else, lol.

    Yes, I did dilute one with alcohol before filtering however they were clear-yellow after the heating process. I combined the aldehyde and methyl anthranilate, mixed them together, put it on the hot plate and watched it carefully as the temp rose. I watched the solution go from being somewhat cloudy and pale yellow to bright yellow and clear, all said it probably took 20-30 minutes. There was a visible water line at the top of the solution.

    In one sample I pipetted the top water layer off of the solution, with the second experiment I diluted with alcohol, mixed with desiccant and filtered. It is possible that the reaction wasn't complete as I don't REALLY know what I'm doing but they both were thicker, clear and bright yellow. I briefly used each one in a few experiments but didn't keep anything so this is all something I'm going to have to revisit.

    I should also add that my experiments were on the 2-3ml scale conducted in a borosilicate 10ml graduated cylinder, no top, cap or cork.

    I don't know, your mileage may vary, It was just one experiment I conducted with each.
    In the future I probably shouldn't comment on this kind of thing as I'm still pretty inexperienced and don't really have any guidance to know what I'm doing or what to look for, just the internet and a whole lot of wishful thinking. I got results that seemed valid and wanted to share and help, in the end I usually feel like a moron for saying anything. That should be my signature at the bottom of every post, hehehe.

    WARNING: This post may or may not contain accurate information!
    Last edited by JEBeasley; 27th January 2014 at 03:21 PM.
    Justin E. Beasley

  18. #18

    Default Re: Schiff's bases

    Have I posted my Schiff's Base Compendium here?
    Paul Kiler
    PK Perfumes
    http://www.PKPERFUMES.com
    Gold Medal for "Best Aroma"; Los Angeles Artisan Fragrance Salon

  19. #19

    Default Re: Schiff's bases

    Justin, please I wasn't trying to make you feel bad. I just thought to make a few things clear that's all. Please don't "feel silly", your enthusiasm shines through.

    Methyl Anthranilate is described as having a fruity, grape odour (and is used in Grape flavours) so maybe by mixing it with Strawberry Aldehyde (aka Aldehyde C16, and Ethyl Methyl Phenyl Glycidate) one boosted the other.

    There are two other chemicals that are called Aldehydes but are not. Aldehyde C14 ( smells of Peach and is really gamma Undecalactone) and Aldehyde c18 (smells of Coconut and is really gamma Nonalactone); they won't make Schiff's Bases either.

    There are a few Schiff's Bases commercially available; Aurantiol (reaction of Methyl Anthranilate with Hydroxcitronellal), a base using Triplal, and ones with Lilial and Lyral. My favourite non-commercial base is made with Aldehyde C12 MNA and Methyl Anthranilate.

  20. #20

    Default Re: Schiff's bases

    Ketones form Schiff's bases, not just aldehydes. It's the carbonyl group that does it. "Aldehyde C-16" has one (and is an ester (and an epoxide!)).

    -innocent whistle-

    There may be other complicating factors I'm overlooking with these particular molecules, but if you got the desired reaction product I would not be surprised, Justin.

    EDIT: The fact that it's an ester instead of a ketone might throw things.

    DOUBLE EDIT: Ah, here we go. The product might not be called a Schiff's base anymore, but I've never been familiar with the exact definition and have been happily accepting the perfumery world's take on it. There are two products, though.

    EDIT FOR THE LAST TME I SWEAR: Lactones undergo a pretty interesting reaction too. Now I'm wondering about C-14 and -18, and of course I left off ordering larger quantities of those yesterday. -sigh-
    Last edited by JayH; 27th January 2014 at 06:30 PM. Reason: Figured this would be a much more straightforward response. Also misspellings, so many.

  21. #21
    Basenotes Plus

    Join Date
    Jul 2013
    Location
    Portland, Oregon
    Posts
    687

    Default Re: Schiff's bases

    Quote Originally Posted by pkiler View Post
    Have I posted my Schiff's Base Compendium here?
    Do you mean the document listing schiff bases and their components? Yes, I believe it's in the big schiff base post from last time. I did download that and haven't done much with it, thanks.
    Justin E. Beasley

  22. #22
    Basenotes Plus

    Join Date
    Jul 2013
    Location
    Portland, Oregon
    Posts
    687

    Default Re: Schiff's bases

    Quote Originally Posted by David Ruskin View Post
    Justin, please I wasn't trying to make you feel bad. I just thought to make a few things clear that's all. Please don't "feel silly", your enthusiasm shines through.

    Methyl Anthranilate is described as having a fruity, grape odour (and is used in Grape flavours) so maybe by mixing it with Strawberry Aldehyde (aka Aldehyde C16, and Ethyl Methyl Phenyl Glycidate) one boosted the other.

    There are two other chemicals that are called Aldehydes but are not. Aldehyde C14 ( smells of Peach and is really gamma Undecalactone) and Aldehyde c18 (smells of Coconut and is really gamma Nonalactone); they won't make Schiff's Bases either.

    There are a few Schiff's Bases commercially available; Aurantiol (reaction of Methyl Anthranilate with Hydroxcitronellal), a base using Triplal, and ones with Lilial and Lyral. My favourite non-commercial base is made with Aldehyde C12 MNA and Methyl Anthranilate.
    Thanks for the reassurance David, not trying to be a drama baby or anything, I felt bad all on my own, I know you didn't mean anything by it. I just don't like misleading people by coming across as an authority on something when I'm not, that's all. If I can own something I will and I'll own it like a boss but this is the internet, there is so much misinformation and without real human contact it's easy to misinterpret, misrepresent, miscommunicate and misunderstand - even when the intentions are good. I'm a fish out of water with chemistry stuff but I like to be helpful so I do feel weird when I screw up, no big deal though, easy enough to move on.

    The clarifications help
    Justin E. Beasley

  23. #23

    Default Re: Schiff's bases

    You were helpful, JEB. I learned a few things in this thread, and you deserve some of the credit.

    David is his usual self, full of reliable information, and it's also nice to have the occasional chemist drop by and keep us in line.

    I personally can't tell Schiff from Shinola.

  24. #24
    Basenotes Plus

    Join Date
    Jul 2013
    Location
    Portland, Oregon
    Posts
    687

    Default Re: Schiff's bases

    Quote Originally Posted by JayH View Post
    Ketones form Schiff's bases, not just aldehydes. It's the carbonyl group that does it. "Aldehyde C-16" has one (and is an ester (and an epoxide!)).

    -innocent whistle-

    There may be other complicating factors I'm overlooking with these particular molecules, but if you got the desired reaction product I would not be surprised, Justin.

    EDIT: The fact that it's an ester instead of a ketone might throw things.

    DOUBLE EDIT: Ah, here we go. The product might not be called a Schiff's base anymore, but I've never been familiar with the exact definition and have been happily accepting the perfumery world's take on it. There are two products, though.

    EDIT FOR THE LAST TME I SWEAR: Lactones undergo a pretty interesting reaction too. Now I'm wondering about C-14 and -18, and of course I left off ordering larger quantities of those yesterday. -sigh-
    So, raspberry ketone will form a schiff base too? With methyl anthranilate, indole or what? Hmmm, so C14 and C18 form a base of some kind but it's not a schiff base? Will heating them speed up the reaction in the same way? I see that I'm going to have to study Paul's compendium and get a stronger hold on this base stuff.
    Justin E. Beasley

  25. #25

    Default Re: Schiff's bases

    Quote Originally Posted by JEBeasley View Post
    So, raspberry ketone will form a schiff base too? With methyl anthranilate, indole or what? Hmmm, so C14 and C18 form a base of some kind but it's not a schiff base? Will heating them speed up the reaction in the same way? I see that I'm going to have to study Paul's compendium and get a stronger hold on this base stuff.
    Heating reactions generally speeds them up unless they're already too fast to make much of a difference, or you're decomposing/boiling off one of the reactants. Looking at Wikipedia, the methyl anthranilate + aldehydes are definitely called Schiff bases, methyl anthranilate + ketones can be called Schiff bases depending who you ask, and indole + aldehydes or ketones are enamines, not Schiff bases, but perfumers call them Schiff bases anyway.

    I'd expect the reactions to go like the attached (as long as they don't require heat or a catalyst to nudge things along). My tablet isn't equipped for churning out illustrations but at least they're clear. [removed incorrect indole reaction]
    Attached Images Attached Images
    Last edited by JayH; 14th February 2014 at 03:35 AM. Reason: incorrect information

  26. #26

    Default Re: Schiff's bases

    Quote Originally Posted by JEBeasley View Post
    Do you mean the document listing schiff bases and their components? Yes, I believe it's in the big schiff base post from last time. I did download that and haven't done much with it, thanks.
    Then it might be a good time to mine the information found there... :-)

    Edited: Oh, You already said that... ...

    PK
    Paul Kiler
    PK Perfumes
    http://www.PKPERFUMES.com
    Gold Medal for "Best Aroma"; Los Angeles Artisan Fragrance Salon

  27. #27

    Default Re: Schiff's bases

    Just for convenience - here's a link to Paul's compendium :

    http://pkperfumes.com/?attachment_id=1246

  28. #28

    Default Re: Schiff's bases

    When I was making Schiff's Bases (just for fun) i used to mix molecular proportions of the two ingredients and warm gently. The reaction occurred pretty rapidly, with a change in colour and viscosity , and a cloudiness which I assumed to be water. Some Schiff's Bases were very highly coloured (Cinnamic Aldehyde or Vanillin Schiff's Base are nearly black). I was never able to get Amyl Cinnamic Aldehyde (ACA) to react, and I assumed that there was some sort of steric hindrance. Whilst theoretically possible I was never able to get any Ketone to work either. I never tried Lactones or Acids ( both with a C=O group), but had been taught they would not work. In school Chemistry formation of a Schiff's base was used to identify an unknown aldehyde or ketone, but a different source of the Amino group was used (2,4-dinitrophenylhydrazine).

  29. #29

    Default Re: Schiff's bases

    I tried citral and methyl anthranilate last night without anything to dehydrate it but heat. It turned a spectacularly bright orange before going dark brown. It didn't cloud while I had it in the water bath, but I haven't had a chance to look at it cooled down yet.

    Only enough methyl anthranilate left for a couple experiments before I have to wait on my order from PW (a good stock of straight indole's coming too, woohoo!). I think I'm going to try ketones just to see if I can get them to go. I have a lot on hand and most of my aldehydes are unfortunately diluted.

  30. #30

    Default Re: Schiff's bases

    JayH,

    raspberry ketone and indole will not react to form a schiff base [an imine].

    schiff bases / imines form because the amine nitrogen acts as a nucleophile
    that will attack the carbonyl carbon, the double bond C=0.
    the amine nitrogen has a pair of electrons to donate, that is why a number of
    schiff base reactions occur without a catalyst.

    anthranilates can be expressed as RNH2
    the two hydrogen's have 1 electron each, so there is a pair to donate,
    indole has the nitrogen bonded between two carbons, and therefore has only one hydrogen,
    so there is only one electron to donate.
    so there would be no way to push the oxygen off of the carbon, so that the C=N
    could ever form.

  31. #31

    Default Re: Schiff's bases

    Err, read what I wrote again and look at my diagrams, and my links. You're correcting something I haven't said. You're also confused on the mechanism.

    EDIT: The mechanism for the reaction between a ketone and a secondary amine, I mean. It's not the same as for a primary amine. [And indole does not react as a typical secondary amine.]
    Last edited by JayH; 14th February 2014 at 03:37 AM. Reason: incorrect information

  32. #32

    Default Re: Schiff's bases

    Quote Originally Posted by JayH View Post
    Err, read what I wrote again and look at my diagrams, and my links. You're correcting something I haven't said. You're also confused on the mechanism.

    EDIT: The mechanism for the reaction between a ketone and a secondary amine, I mean. It's not the same as for a primary amine.
    my point was the product is NOT a schiff base, it is an enamine, as you did mention,
    so perfumers should not call the product a schiff base.

    i am not confused with the mechanism, i only explained the attack from a primary amine use
    the second deprotonation comes from one of the hydrogen electrons in the adjacent carbon, when using a secondary amine
    like indole.

    i didnt say your diagram was wrong......

    i suppose it might have been much easier to simply say that perfumers
    shouldn't call the product in your diagram a schiff base, rather than trying to explain why

    that's all ......

  33. #33

    Default Re: Schiff's bases

    I'm terribly sorry, I didn't realize. My apologies for being overly sensitive. I wasn't even sure what I was supposed to have gotten wrong. I get that way sometimes when I'm confused.

    You're right, products from indole are not Schiff bases. I'd prefer not to call them that myself (condensation products, maybe?), but it's one of those cases where I'm torn between strict usage and deferring to tradition.

  34. #34

    Default Re: Schiff's bases

    JayH,

    no need to apologize, it just wrote my reply wrong....

    peace

  35. #35

    Default Re: Schiff's bases

    Luigi how do I get Vanillyl isobutyrate (Isobutavan) which is an aldehyde, to react with methyl anthranilate? I've tried heating on a water bath but with no observable reaction, no cloudiness. Is there a catalyst I can use ?

  36. #36

    Default Re: Schiff's bases

    Quote Originally Posted by Kennel No5 View Post
    Luigi how do I get Vanillyl isobutyrate (Isobutavan) which is an aldehyde, to react with methyl anthranilate? I've tried heating on a water bath but with no observable reaction, no cloudiness. Is there a catalyst I can use ?
    Kennel,

    that is a good question, looking at the structure is looks more like an ester though?

  37. #37

    Default Re: Schiff's bases

    Luigi
    Yes its an ester at one end of the benzene molecule but an aldehyde at the other as is vanillin.
    K5

  38. #38

    Default Re: Schiff's bases

    Much as I would love to discuss the minutiae of Organic Chemistry, I don't think that this is the best place to do it; do you? For the per poses of this discussion I do not care abut the mechanism of Schiff's Base formation, nor whether a specific chemical be called a Schifff's Base or not, nor how Schiff's Bases are made commercially. All I'm interested in, here, is trying to help those who would like to make a Schiff's Base by mixing a couple of chemicals together. And I will repeat that some are easier to make than others. It may well be, theoretically possible to make a Schiff's Base from Aldehyde C16; but for the amateur it isn't. Methyl Anthranilate reacts with most Aldehydes (and not all) with ease; it does not react with Esters, Acids, Lactones or Ketones in the same way. Ditto, Indole; very difficult to make Indolene in the amateur workroom.

  39. #39

    Default Re: Schiff's bases

    I'm pretty discouraged anyway.. It seems that the process is a bit too involved for me right now
    (not sure where to get desiccants), and the results don't smell too different, nor last longer..
    Would have been nice if there was a blue base, but doesn't seem there is, so I don't really
    get the point anymore.. :\

  40. #40

    Default Re: Schiff's bases

    Nizan you really shouldn't be discouraged. I've successfully made many Schiff base products with chemicals such as scentenal, canthoxal, safranal, benzaldehyde and other aldehydes (isobutavan still the exception). Don't be concerned about using desiccants or getting rid of the water produced by the reaction. I make a 10% solution in alcohol of the Schiff base once the reaction is complete and then use it in formulation. Given the small amount of the Schiff base used in an overall formulation the amount of water from the reaction is insignificant. There will be more water in your alcohol.
    On your question about making an aldehyde more "long lived" by reacting it with methyl anthranilate, the resulting Schiff base will be well removed in odour from the original aldehyde. For a real base note aldehyde use muguet aldehyde or adoxal.

  41. #41

    Default Re: Schiff's bases

    What is a "blue base"? What has the colour got to do with it? Or do you mean that it is a base that makes you sad?

    It is very simple to make several Schiff's Bases; that is what I was trying to point out. The only problem is removing the water that is produced, and there are ways around that. If you can buy several obscure Aromachemicals and Essential Oils I am sure it is not beyond your capability to get hold of some anhydrous Sodium Sulphate.

    If you think that the Schiff's Base smells like the two original chemicals used, then it means you have not made the Base properly. A Schiff's Base lasts much longer, and is a Base note supreme. It is also a fixative. Schiff's Bases are try useful, and are worth exploring.

  42. #42

    Default Re: Schiff's bases

    The Indolene I bought doesn't seem that strong to me or long lasting. Is that typical of Indolene or is it perhaps a bad sample of it? From what I've observed, I don't consider either Indole or Hydroxycitronellal as true base notes (more like mid-base notes), but am I wrong in expecting that Indolene should last longer than both do individually?

  43. #43
    Basenotes Plus

    Join Date
    Jul 2013
    Location
    Portland, Oregon
    Posts
    687

    Default Re: Schiff's bases

    Quote Originally Posted by David Ruskin View Post
    What is a "blue base"? What has the colour got to do with it? Or do you mean that it is a base that makes you sad?

    It is very simple to make several Schiff's Bases; that is what I was trying to point out. The only problem is removing the water that is produced, and there are ways around that. If you can buy several obscure Aromachemicals and Essential Oils I am sure it is not beyond your capability to get hold of some anhydrous Sodium Sulphate.

    If you think that the Schiff's Base smells like the two original chemicals used, then it means you have not made the Base properly. A Schiff's Base lasts much longer, and is a Base note supreme. It is also a fixative. Schiff's Bases are try useful, and are worth exploring.
    David speaks the truth, I got my desiccant from an online vendor of
    biodiesel supplies: http://www.dudadiesel.com/search.php...ium+sulfate%22

    They are easy to find once you know what to look for: http://en.wikipedia.org/wiki/List_of_desiccants

    I also have some Calcium Chloride I have not tried yet.

    It would be great to know how to make some of these other bases as in what type of catalysts are needed, temps, etc
    Justin E. Beasley

  44. #44

    Default Re: Schiff's bases

    Quote Originally Posted by Renegade View Post
    The Indolene I bought doesn't seem that strong to me or long lasting. Is that typical of Indolene or is it perhaps a bad sample of it? From what I've observed, I don't consider either Indole or Hydroxycitronellal as true base notes (more like mid-base notes), but am I wrong in expecting that Indolene should last longer than both do individually?
    Smell is so subjective. I find Indole and Indolene very strong indeed (INdolene is softer and more floral; the rough edges have been rounded off) whilst Hydorxycitronellal fairly strong. I do remember the first time I smelled Hydroxycitronellal I could barely detect it, and I think it was because I couldn't describe it to myself, and had never smelled anything like it before. Once I had learned its smell, I found it unmistakeable, and an obvious presence. Indole solution on a smelling strip will last for days, so I have always classed it as a Middle/Base note material. I would class Indolene, in the same way. As it is a larger molecule you would expect Indolene to last longer than Indole.

  45. #45

    Default Re: Schiff's bases

    Thanks David and Kennel! I guess I misunderstood David's initial reply.
    Now I need to get me some MA.. I guess I could do a few drops of each
    of the components, as I don't have enough of the aldehydes I want to
    play with (for some reason neither PA nor Hermitage sell phenyacetaldehyde)..

    What is a "blue base"? What has the colour got to do with it? Or do you mean that it is a base that makes you sad?

    You made me seriously laugh! I meant a blue color.. It would be nice to have
    blue (colored) components in the mix.. Or even purple!

    I guess I can initially leave the water in the mix, if I work in high dilutions..
    And later, I could dissolve in alcohol and add desiccants.. (Can't I freeze the
    water out somehow?).

  46. #46

    Default Re: Schiff's bases

    Quote Originally Posted by David Ruskin View Post
    Much as I would love to discuss the minutiae of Organic Chemistry, I don't think that this is the best place to do it; do you?
    We're discussing synthesis, so yes, it absolutely is. Understanding the reactions helps a lot when exploring new possibilities and allows for less common aromachemicals to be produced from readily available ones. You may not be interested in certain details; that's fine just as I'm not really interested in others. Hearing about someone else's experience with a reaction is always helpful. But this sort of theoretical discussion as well is quite useful.

  47. #47

    Default Re: Schiff's bases

    Quote Originally Posted by Nizan View Post
    I guess I can initially leave the water in the mix, if I work in high dilutions..
    And later, I could dissolve in alcohol and add desiccants.. (Can't I freeze the
    water out somehow?).
    You can heat the water out. Perfumer's World has phenylacetaldehyde.

  48. #48
    Basenotes Plus

    Join Date
    Jul 2013
    Location
    Portland, Oregon
    Posts
    687

    Default Re: Schiff's bases

    Quote Originally Posted by JayH View Post
    You can heat the water out. Perfumer's World has phenylacetaldehyde.
    That was what I noticed when I was intentionally trying to oxidize the C11 base by heating/boiling, I don't think it did much in the way of oxidizing it but it definitely boiled the water off. Actually, regardless of whether or not it oxidized I think the resulting base smelled pretty good and it definitely didn't hurt it. So, just for the record, you can cook the heel out of a C11 base and it won't hurt it as long as it doesn't solidify, lol. I think I kept it somewhere in the range of 50-70C as I never set my hot plate over that temp.
    Justin E. Beasley

  49. #49

    Default Re: Schiff's bases

    Quote Originally Posted by JayH View Post
    You can heat the water out. Perfumer's World has phenylacetaldehyde.
    That's where I got mine.. But they were kind of weird - they sent it a month after I layed them and they don't respond to inquiries (such as - why was half of the benzaldehyde solid white..).. Would have been nice to have better options.

  50. #50

    Default Re: Schiff's bases

    Quote Originally Posted by JayH View Post
    We're discussing synthesis, so yes, it absolutely is. Understanding the reactions helps a lot when exploring new possibilities and allows for less common aromachemicals to be produced from readily available ones. You may not be interested in certain details; that's fine just as I'm not really interested in others. Hearing about someone else's experience with a reaction is always helpful. But this sort of theoretical discussion as well is quite useful.
    As this is a DIY forum to discuss Perfumery, I do not think that you comparing the size of your retort stands with each other is of much use. This Forum is not about Organic Chemistry or Chemical Synthesis, it is about Perfumery.

  51. #51

    Default Re: Schiff's bases

    Quote Originally Posted by Nizan View Post
    That's where I got mine.. But they were kind of weird - they sent it a month after I layed them and they don't respond to inquiries (such as - why was half of the benzaldehyde solid white..).. Would have been nice to have better options.
    If half of the Benzaldehyde was solid white, it was half Benzoic Acid.

  52. #52

    Default Re: Schiff's bases

    Quote Originally Posted by JayH View Post
    We're discussing synthesis, so yes, it absolutely is. Understanding the reactions helps a lot when exploring new possibilities and allows for less common aromachemicals to be produced from readily available ones. You may not be interested in certain details; that's fine just as I'm not really interested in others. Hearing about someone else's experience with a reaction is always helpful. But this sort of theoretical discussion as well is quite useful.

    There's always the private messaging facility for continuing discussions that have become off topic to the thread.

  53. #53

    Default Re: Schiff's bases

    We don't argue with moderation decisions.

    http://www.basenotes.net/content/92-...ct-for-Members

  54. #54

    Default Re: Schiff's bases

    Quote Originally Posted by David Ruskin View Post
    As this is a DIY forum to discuss Perfumery, I do not think that you comparing the size of your retort stands with each other is of much use. This Forum is not about Organic Chemistry or Chemical Synthesis, it is about Perfumery.

    Posts arguing with moderation requests are deleted and are inclined to lead to suspension.

    Please feel free to discuss any subject by private message or even start a new thread or Group for discussing chemistry issues.

  55. #55

    Default Re: Schiff's bases

    Hmm.. So much drama..

    Anyhow, I think I'll try benzaldehyde and indole today.. How warm do you usually make things
    to get a reaction in a reasonable time? I thought just of putting the vial in a bath at around 40-50
    Celsius. I'm going to make a small amount (I guess around 20 mg) - should I also dilute it before
    the reaction?

    Thanks

    Update - done! It's red and smells like benzaldehyde (although much weaker) and indole/indolene..
    Last edited by Nizan; 2nd February 2014 at 06:45 PM.

  56. #56

    Default Re: Schiff's bases

    Quote Originally Posted by Nizan View Post
    Hmm.. So much drama..

    Anyhow, I think I'll try benzaldehyde and indole today.. How warm do you usually make things
    to get a reaction in a reasonable time? I thought just of putting the vial in a bath at around 40-50
    Celsius. I'm going to make a small amount (I guess around 20 mg) - should I also dilute it before
    the reaction?

    Thanks

    Update - done! It's red and smells like benzaldehyde (although much weaker) and indole/indolene..

    Did it undergo a change? Exhibit heat or color change?
    Last edited by pkiler; 3rd February 2014 at 06:02 AM.
    Paul Kiler
    PK Perfumes
    http://www.PKPERFUMES.com
    Gold Medal for "Best Aroma"; Los Angeles Artisan Fragrance Salon

  57. #57

    Default Re: Schiff's bases

    I warmed it, so I don't know if it heated.. It became thick and very deep raspberry red..
    Doesn't seem like it's long lived on a strip - even though the strip is red, I can't really
    smell it anymore (though my nose could be fried, and I checked it in 10% dilution).
    I also did the same with phenylacetaldehyde..

  58. #58

    Default Re: Schiff's bases

    That particular red color change seems to be Indole related, if I remember right, but can't remember if the color change is because of a Schiff base forming, or because of the indole doing something odd all by itself...
    Paul Kiler
    PK Perfumes
    http://www.PKPERFUMES.com
    Gold Medal for "Best Aroma"; Los Angeles Artisan Fragrance Salon

  59. #59

    Default Re: Schiff's bases

    Hmm.. could be - as the almond smell evaporates pretty quickly..
    On the other hand, the phenyacetaldehyde didn't turn red - it turned amber..
    And I like the effect in the latter much better - it gave it some herbal depth.
    How can I tell if a new molecule was formed? I thought the stickiness would
    be a good indication, but it seems the longevity didn't improve..

  60. #60

    Default Re: Schiff's bases

    Quote Originally Posted by pkiler View Post
    Have I posted my Schiff's Base Compendium here?
    Paul, absolutely brilliant Schiff's Base Compendium. Thank you for putting such a great document together and for making it available. I am enjoying working through the different combinations and seeing and smelling the effects. I have yet to actually figure out how one gets the mixture to clear. Once they return to cool they go cloudy, which I understand is the H2O. Just not clear HOW to use the desiccant to remove the H20.

    (p.s. - Also wanted to mention I recently purchased a fantastic pair of Koure frames, I know you are someone that would appreciate that from a post I read somewhere.

Similar Threads

  1. No Shipping Perfume from US to military bases??
    By Elf in forum Male Fragrance Discussion
    Replies: 8
    Last Post: 28th February 2013, 06:52 AM
  2. Powdery bases
    By Javiero in forum Fragrance DIY
    Replies: 19
    Last Post: 6th September 2012, 08:59 PM
  3. What is a schiff base?
    By princeOK in forum Fragrance DIY
    Replies: 20
    Last Post: 20th April 2012, 01:54 AM
  4. Perfume Bases/Carriers
    By PattiMcW in forum Fragrance DIY
    Replies: 4
    Last Post: 25th March 2010, 05:52 AM
  5. Ten to Cover All the Bases
    By trumpet_guy in forum Male Fragrance Discussion
    Replies: 2
    Last Post: 29th December 2005, 07:36 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •