First 1-(2,4,5-trimethoxyphenyl)-2-nitropropene was reduced to the oxime using low-pressure hydrogenation, then the isolated oxime was reduced to the amine using CTH (ammonium formate/Pd-C).
The yield sucks big time. 1,8 g TMA-2 HCl from 10 g oxime.
25,3 g 1-(2,4,5-trimethoxyphenyl)-2-nitropropene (100 mmol), 50 ml EtOAc, 18 ml (300 mmol) acetic acid and 125 mg 5%Pd/Al
2O
3 (0,5% w/w catalyst to substrate) was stirred under a 15 psig hydrogen atmosphere for about two hours. Celite (2 teaspoons) was added and the catalyst removed by vacuum filtration. The solvent was then removed to yield 22,5 g oxime (94%).
10 g 1-(2,4,5-trimethoxyphenyl)-2-propanone oxime (42 mmol), 1 g 5%Pd/C and 100 ml MeOH was added to a rb flask equipped with a condenser and a stirbar. Ammonium formate 13.25 g (210 mmol) was added in three portions over two hours time while the reaction temperature was kept at 55°C. After about four hours the gas evolution had almost ceased. The catalyst was removed by vacuum filtration (celite) and the solvent removed by distillation. To the oily semi-crystalline residue was added 50 ml toluene and enough 5% HCl to bring the pH to 5. The organic layer was removed and the aqueous solution made alkaline (pH 12), saturated with NaCl and extracted twice with 30 ml toluene. The combined toluene extracts was dried over MgSO
4 and dry HCl/IPA was added to pH 5.5 (damp universal pH paper). 1,8 g TMA-2 collected
Edit: Oops, forgot the acetic acid.....Now, there it is.
Catalytic hydrogenation freak