We report herein the synthesis of impurity B of Flumazenil via demethylation, benzyl protection, cyclization and debenzylation from 7-methoxyl-3,4-dihydro-4-methyl-2H-1,4-benzo-diazepine-2,5（1H）-dione. The structure...We report herein the synthesis of impurity B of Flumazenil via demethylation, benzyl protection, cyclization and debenzylation from 7-methoxyl-3,4-dihydro-4-methyl-2H-1,4-benzo-diazepine-2,5（1H）-dione. The structure of impurity B of Flurnazenil was confirmed by 1n N/V[R, 13C NMR and HRMS, and the overall yield was 29.3%. The finding will be helpful for optimizing the synthetic process and quality control of Flumazenil.展开更多
文摘We report herein the synthesis of impurity B of Flumazenil via demethylation, benzyl protection, cyclization and debenzylation from 7-methoxyl-3,4-dihydro-4-methyl-2H-1,4-benzo-diazepine-2,5（1H）-dione. The structure of impurity B of Flurnazenil was confirmed by 1n N/V[R, 13C NMR and HRMS, and the overall yield was 29.3%. The finding will be helpful for optimizing the synthetic process and quality control of Flumazenil.
