反应详情

According to the general procedure (GP10), microwave-assisted Pictet-Spengler reaction (60 W; 140° C.; 6.5 bars; 10 min.) between 2-(2-ethyl-4-iodo-imidazol-1-yl)-ethylamine (6.340 mmol) and 3-(2,5-difluoro-4-trifluoromethyl-phenyl)-propionaldehyde (1.509 g; 6.340 mmol) afforded 8-[2-(2,5-difluoro-4-trifluoromethyl-phenyl)-ethyl]-3-ethyl-1-iodo-5,6,7,8-tetrahydro-imidazo[1,5-a]pyrazine. LC-MS: tR=0.79 min.; [M+H]+=485.87 g/mol. Subsequent protection of the secondary amine, and purification by FC (DCM/MeOH=50/1) allowed the isolation of the pure product 8-[2-(2,5-difluoro-4-trifluoromethyl-phenyl)-ethyl]-3-ethyl-1-iodo-5,6-dihydro-8H-imidazo[1,5-a]pyrazine-7-carboxylic acid tert-butyl ester as a slightly beige solid (1.890 g; 51%). LC-MS: tR=0.99 min.; [M+H]+=585.78 g/mol.