反应详情

温度

85 °C

To a 800 ml pressure flask was added tris(dibenzylideneacetone)dipalladium (2.64 g, 2.88 mmol), 2-(di-t-butylphosphino)biphenyl (1.42 g, 4.75 mmol) and sodium tert-butoxide (17.5 g, 182 mmol). Then dry THF (500 mL), 4-bromo-2-ethyl-6-nitroaniline (30.0 g, 130 mmol) and morpholine (34 ml, 390 mmol) were added. Argon was bubbled through the solution for 1 minute and the flask was sealed. The reaction mixture was stirred at 85° C. for 3 days. THF was evaporated in vacuo and the crude product was preabsorbed on silica and this then transferred on top of a silica gel column. Elution with hexane-ethyl acetate (6:4 to 4:6 to 0:1 gradient) gave, after evaporation of solvents, the title compound (15.2 g red-brown solid, 49.3%). LCMS (M+H)+ m/z 238 (t=0.64 min.) 1H NMR (500 MHz, DMSO-d6) δ 7.32 (1H, s), 7.22 (1H, s), 6.96 (2H, s), 3.72 (4H, broad s), 2.96 (4H, broad s), 2.21 (3H, s). Procedure for the Preparation of 4-(3-amino-5-methyl-4-nitro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester

1. customArgon was bubbled through the solution for 1 minute
2. customthe flask was sealed
3. customTHF was evaporated in vacuo
4. customthe crude product was preabsorbed on silica
5. washElution with hexane-ethyl acetate (6:4 to 4:6 to 0:1 gradient)
6. customgave
7. customafter evaporation of solvents
8. customLCMS (M+H)+ m/z 238 (t=0.64 min.) 1H NMR (500 MHz, DMSO-d6) δ 7.32 (1H, s), 7.22 (1H, s), 6.96 (2H, s), 3.72 (4H, broad s), 2.96 (4H, broad s), 2.21 (3H, s)
9. customProcedure for the Preparation of 4-(3-amino-5-methyl-4-nitro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester