which is easier/betterhexamine or nitro reduction?

[Chromic]

Terbium has run the AmCl/HCHO reaction. I have run the hex/HCl reaction. There might be slight differences in the temperatures between these two reactions because the hex/HCl variation has a bit more AmCl equivilant than the AmCl/HCHO version.

The way I ran this reaction to test out Terbium's suggestion was over the course of three days. As each day progressed, I would turn the heat up a bit more. After stirring at 104C for a day, nothing happened. I went up to ~104C vapor temp (this is 110-115C liquid temp) and the mixture started bubbling as I normally saw when hitting this temperature faster (mostly gas bubbles, some vapor bubbles).

Keep in mind that the "work up" of this reaction requires the distilling pot to be boiled dry, so except for time spend at each temperature, there was no difference in the overall method. There was also no difference in the approximate yields.

The odd thing is that both Terbium and I stand by our recommendations. I think the best piece of advice is to simply "go very slow" with heating.

Honestly, this is a pretty hard reaction to fuck up. Eleusis did it on a hotplate with a frying pan and still got some sort of product that could be used for amination. (*but do not do this, your product will contain significant amounts of inactive N,N-dimethyl- product*)

[terbium]

The way I ran this reaction to test out Terbium's suggestion was over the course of three days. As each day progressed, I would turn the heat up a bit more. After stirring at 104C for a day, nothing happened. I went up to ~104C vapor temp (this is 110-115C liquid temp) and the mixture started bubbling as I normally saw when hitting this temperature faster (mostly gas bubbles, some vapor bubbles).
The reaction mixture is not supposed to bubble. The reaction happens at a liquid temperature of 104 C even though there is no overt indication that anything is happening.

Keep in mind that the "work up" of this reaction requires the distilling pot to be boiled dry, so except for time spend at each temperature, there was no difference in the overall method.
Which procedure calls for the pot to be boiled dry? The procedures in Vogel and Organic Syntheses certainly do not. The procedures given in Vogel and Organic Syntheses are nearly identical and it has been my experience that the procedures given in Vogel and Organic Syntheses are very reliable. I don't understand why anyone would follow some procedure that is materially different from the ones given in Vogel and Organic Syntheses.

http://www.orgsyn.org/orgsyn/prep.asp?prep=cv1p0347

Baseline Does Not Exist.

[abacus]

I carried out the hexamine (700g) with HCL synth.  The flask temperature was held at around 104DegC for over 6 hours.

Small amount of gas was emitted and minimal bubbling noticed in the flask and was not refluxing.

Then reduced the volume under reduced pressure to half, filtered am.cl, further reduced liquid under reduced pressure.

The flask contents temperature was never allowed to exceed 110DegC except right at the end for a couple minutes at most.

Recrystalised 220g meam.hcl from 1L methanol.

Abacus

[Chromic]

Orgsyn say to reduce the volume as far as possible--until it becomes a thick paste. I just kept boiling until it was dry... it was easier.

[terbium]

Orgsyn say to reduce the volume as far as possible--until it becomes a thick paste. I just kept boiling until it was dry

This is only after several previous steps and much of the methylamine has already been recovered.

Organic Syntheses says the post 104°C reaction workup is:

1) Cool to room temperature and filter off precipitated ammonium chloride.
then
2) Heat on a steam bath until the volume has been reduced by half then cool and filter off more ammonium chloride.
then
3) Concentrate again using heat and reduced pressure (water aspirator) until a scum starts to form on the top of the liquid then cool to room temp and collect a first crop of methylamine.
then
4)Concentrate again with heat and reduced pressure to 2/3 of previous volume then cool to room temp to obtain a second crop of methylamine.
It is only now, after 4 previous steps of concentration and filtration, that the solution is concentrated to a thick syrup and extracted with chloroform to obtain a last little bit of methylamine. I never bothered with this fifth round of concentration for the small amount of methylamine that was recovered from this step.

Again I can't emphasize enough that the Organic Syntheses procedure should be followed as closely as possible. The specified temperatures should be maintained and each step should be followed. Shortcuts should not be taken. If the procedure calls for five stages of concentration and crytallization it should not be shortened to one. The five stages are there not by whim but for a precise reason.
Baseline Does Not Exist.