PRE-CHRISTMAS UPDATE...AND CHLOROETHANOL! (Patreon)

Well kids, Christmas miracles do happen! I passed all of my classes somehow, and you know what that means: it's time to shove as much chemistry as possible into that single month between fall and spring semesters!

Now, there are a few big syntheses I want to try out, and two of them require the same starting material, seen in the image above. Those synths are for acetylcholine and novocaine (procaine), and the chemical I need is 2-chloroethanol. This is an important precursor to N-substituted ethanolamines, which form whenever you add it to certain amines (in my case, diethylamine and trimethylamine).

Making 2-chloroethanol was an interesting, yet very wasteful, endeavor. The only hobbyist-friendly pathway involves bubbling hydrogen chloride through ethylene glycol at 100C, which takes basically all day and only uses up a tiny fraction of the starting glycol. And worse yet, water forms alongside our product. This might not seem bad...until you realize 2-chloroethanol forms a 41% azeotrope with water! I tried using anhydrous sodium sulfate to dry it up, but very little was absorbed. The initial distillation off of the glycol also has to be run fairly hot, and isn't exactly fast. AND, to top everything off, 2-chloroethanol is actually quite toxic, so extra care had to be taken.

In the end, following several distillations, I wound up with 16g of pure 2-chloroethanol and 30g of the azeotrope. Since I started with roughly 200g of ethylene glycol, the yield came out to an abysmal 11%. I plan to use all of the pure stuff to make the diethylaminoethanol (or DEAE) for novocaine, so this synth better work...I don't have a lot of redo ability lol. And speaking of...

How does one get diethylamine to react with their 2-chloroethanol?? Well, it's actually beautifully easy: you just react DEET bug spray with sodium hydroxide and distill it off! This preparation is so useful and high-yielding, I think it deserves its own video...here's hoping the FBI doesn't think I'm making LSD with it, haha!

For the final steps of making novocaine, I have to esterify p-aminobenzoic acid (PABA) with the DEAE in the presence of an acid. Planning this step has actually proven to be the hardest part of the synthesis, because very little data seems to exist about this reaction. Normally (like when you're synthesizing benzocaine, which just swaps the DEAE with ethanol), you'd need an excess of the alcohol, but I won't have much to spare. After talking to NurdRage and a few other chemists, I think this is the procedure I've settled on: the PABA and DEAE will be mixed stoichiometrically (no excess of either), and added to xylene or toluene with sulfuric acid. Heating should cause water to distill off azeotropically with the xylene/toluene, and a Dean-Stark trap will collect the water as it separates. We'll see how it goes though, wish me luck!

Also, for upcoming content, I should be finishing the diacetyl popcorn video in the next week or so, and then I'll be doing fluorine, followed by thioacetone and maybe novocaine...or tellurium chem? Idk how I'll release things later on the list, lol