How to Synthesize Vanillin Oxime for Vanilla Amine

TL;DR

Vanillin oxime is synthesized by dissolving 5 grams of hydroxylamine hydrochloride and 10.55 grams of anhydrous sodium acetate in 90 milliliters of distilled water, adding 9.8 grams of vanillin, and refluxing for 20 minutes. It is intended as a precursor to vanilla amine for making spicy capsaicinoid compounds, though the follow-up reaction failed across three methods. See why the oxime synthesis is still worthwhile on its own.

Transcript

okay so after a few requests i think it's appropriate to actually release the vanillin oxime video this video's actually been sitting on my hard drive for a while and i guess it's time for it to be released the major reason why i didn't release it is because the vanillin oxime is supposed to serve as a precursor for something called vanilla amine t... Read More

Key Insights

• 🌶️ The video highlights the importance of synthesizing vanillin oxime as a precursor for producing vanilla amine, used in the synthesis of spicy compounds.
• ❓ Despite unsuccessful attempts at synthesizing vanilla amine, the synthesis of vanillin oxime itself is still interesting and has its own merits.
• 🎮 The video provides a detailed explanation of the synthesis process, including the role of each chemical involved and the necessity of an acidic buffer solution.
• 🌱 The presenter plans to discuss oximes further in a future video, particularly in the context of nylon synthesis.

Questions & Answers

Q: How do you make vanillin oxime?

Dissolve 5 grams of hydroxylamine hydrochloride and 10.55 grams of anhydrous sodium acetate in 90 milliliters of distilled water, stirring until clear. Add 9.8 grams of vanillin, then reflux the mixture in an oil bath for 20 minutes. Vanillin reacts with the hydroxylamine hydrochloride to form vanillin oxime, hydrochloric acid, and water.

Q: What is vanillin oxime used for?

It is intended to serve as a precursor for vanilla amine, which in turn is a precursor for making spicy compounds and capsaicinoids like capsaicin. Even though it was not successfully carried through to vanilla amine, the presenter notes that synthesizing vanillin oxime is interesting and has merits on its own.

Q: What is an oxime?

An oxime is a carbon double bonded to a nitrogen with an OH group attached to the nitrogen. It is generated from ketones or aldehydes, which are a carbon double bonded to an oxygen. In this synthesis the aldehyde group of vanillin is converted into the oxime.

Q: What role does sodium acetate play in the synthesis?

Sodium acetate sequesters the hydrochloric acid released by the hydroxylamine hydrochloride during the reaction, forming an acidic buffer. This keeps the strong acid from interfering with the reaction. Anhydrous sodium acetate was used, but sodium acetate trihydrate works too if you adjust the amount.

Q: Why is the reaction heated to reflux?

Heating greatly increases the reaction rate and helps the poorly water-soluble vanillin dissolve into solution. Under reflux, water vapor is recondensed by a condenser so no water is lost while boiling. Without heat, the reaction would leave a mess of unreacted vanillin and could take hours or days to approach completion.

Q: Why did the vanilla amine synthesis fail?

The intended final step was reducing the oxime's N-OH group down to an NH2 to form vanilla amine. The presenter tried three distinct methods, each twice, and none produced vanilla amine. They are still working on a reliable synthesis and hope it can come from vanillin oxime.

Q: What form of sodium acetate can you use?

The video used anhydrous (water-free) sodium acetate, but the more easily obtained sodium acetate trihydrate can also be used. If you use the trihydrate, you need to do a little math to calculate how much is required. The presenter notes sodium acetate is easy to make by mixing vinegar and baking soda.

Q: Where can you get the vanillin for this reaction?

The vanillin used was purchased from AliExpress. Alternatively, you can use vanillin extracted from vanilla sugar, as shown in a previous video. The hydroxylamine hydrochloride is more involved to prepare, and the presenter plans to cover making both it and sodium acetate in a future video.

Summary & Key Takeaways

• The video showcases the synthesis of vanillin oxime, intended as a precursor for vanilla amine, a compound used in the synthesis of spicy compounds like capsaicinoids.

• Despite several attempts using different methods, the desired compound of vanilla amine could not be successfully synthesized.

• The video highlights the process of synthesizing vanillin oxime, the role of each chemical involved, and the challenges faced in achieving the desired outcome.