May be I'll check your nitrostyrene method, it's atractive but it's not good to use and untested method if you are trying a new rxn, if it doesn't work you don't know the step that failed.
About 2,5 DMNS, 1:1.1:0.06 aldehyde:nitromethane:cycloehxylamine 24 hours give a 50-60 % of nitrostyrene, but 1:1.1:0.2 about a 100% of a mixture of aldehyde and other compund, deep orange, almost red, amorphous, not very soluble in IPA. 1:1.1:0.06 in methanol gave nitrostyrene, but TLC showed a little spot of a impurity. Better use an known method for this first attempt. This nitro is orange.
I think that you got some amine, the change of color during the addition to the NaBH4 is ok, and the rest of rxn seems to had worked ok, probably you have amine and other byproducts that have interfered in the xtallyzation, so you should add water, discard the ether, basify and extract again, dry and xtallize.
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Ok, my sol was yellow but after some of the solvant was evaporated it turned orange. I thought it was decomposition so I stopped the evap there and let some Et2O with it. I will try to evap the Et2O next time under reduced pressure at water pump on a water bath. Do I have to put some boiling stone ( altough I have read that it doesn't work for reduced pressure distillation) or a capillary to reduce bumping?
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Probably there's some decomposition, or are impurities of the nitro. I've done the rxn exactly like described by Beaker, and the nitroethane after evaporation of ether with the aspirator was a brownish yellow, sometimes more dark or less, or more orange. You can use magnetic stirring to evaporate the ether, but sometimes I've evaporated it without stirring and without capillary, but of course it is a good idea.
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The reaction is like you say, with gas bubbling etc... The first time I've done it there was some residue in the condensor like you say but not this time. One mistake I have done is that in the first hour the tube was not put correctly and there was a leak in it, so some O2 may have entered in the reaction but I think it's not too bad because in the file cth.txt on rhodium's site they say that argon atmosphere is not needed.
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If methanol is boiling no 02 can enter in the rxn, but I guess it won't interfere anyway. I've used the stirrer but I think like you it is not stricly necessary because the boiling methanol mix everything completely.
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My Amform was done like this: I mixed some 20% NH4OH and some 85% ac formic in a beaker until pH was 6-7, put the heat on with a ventilator and evaporated the water. At a time I got some heavy fume, I stopped it here, it crystalized, I scrapped the crystals, vacuum filtered them and washed them with plenty acetone. I put them for a night in vacuum, I think that they are dry enough.
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You made a good work to do it.
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I used 250mg 10% commercial Pd/C 50% wet, so 125mg of Pd/C for ~4g of nitroethane, I think this is not a too low amount, how much have you used?
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I think it's ok , but with this amoutn acording with beaker will be better to keep the rxn refluxing 24 hours. Sometimes I've used more Pd/C to make the rxn shorter.
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What is the colour of the sol after the filtration of the Pd/C and before the work up?
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Slightly yellow, almost colorless.
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I'm disgusted of gassing and next time I will do your sulfate with IPA.
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I prefer to make the sulfate with this amine, it's ok for the next step.
My workup has been filter, evaporate methanol, residue was brownish, add water, wash with dcm, basify, extract with ether/toluene, dry and make the salt. With H2SO4 try to keep pH in 6, although if it is lower the only problem is that you can get more bisulfate.
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Another thing: what can be the gelatin like emulsion at the interlayer when the pH is too high? any idea?
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Don't worry, for us are byproducts, discard them.
If you are working with a few grams you can considere the option of reduce the nitro with Zn/HCl, it's one step and very easy. It uses a lot of solvent in the workup, but it's almost the same with beaker procedure.
Good luck and be patient.