From Rhodium's site, the microwave Henry condesation text:
"...
Several reagents such as phthalic anhydride,[12,13] methanesulfonyl
chloride,[14] dicyclohexylcarbodiirnide (DCC), [15] pivaloyl chloride, [16,
17] ammonium acetate-acetic acid [18, 19] and amines[7, 19] have been used
for the dehydration of the ensuing b-nitro alcohols. ..."
I was thinking that the mere addition of the formaldehyde to the nitroethane with ammonium acetate and acetic acid would afford the nitropropene directly. Perhaps even the addition of microwave heating would improve yields or speed up the process. I can't imagine that nitropropene reacts too differently from other nitropropenes...
If one were to use a substituted ring one could substitute the nitroethane with nitromethane (which is easier to obtain OTC) and produce a substituted phenethylamine.
?