3-Bromo-1,3,4,5-tetrahydro-2H-benzo[b]azepin-2-one

The Uses of 3-Bromo-1,3,4,5-tetrahydro-2H-benzo[b]azepin-2-one

3-Bromo-1,3,4,5-tetrahydro-2H-benzo[b]azepin-2-one is an intermediate in the synthesis of Benazepril Hydrochloride. Benazepril Hydrochloride is a first-line antihypertensive drug recommended by the WHO. It is a chiral drug with excellent clinical efficacy, strong safety and tiny side effects in the international antihypertensive drugs of angiotensin converting enzyme inhibitors.

Chemical properties

White or almost white crystalline

Preparation

The preparation of 3-Bromo-1,3,4,5-tetrahydro-2H-benzo[b]azepin-2-one is as follows:10 parts by weight of the heated melted polyphosphoric acid was added to the drying kettle, With stirring, The above 2-bromo-3,4-dihydro-N-hydroxy- (2H) -naphthalimide was added in portions at a temperature of 60 ° C, Insulation reaction for 20 hours; The reaction solution was added dropwise to 12.5 parts by weight of water to carry out hydrolysis, Still Washed to give 3-bromo-1,3,4,5-tetrahydro-2H-1-benzazepin-2-one crude; 10 parts by weight of methanol and 0.1 part by weight of activated carbon were added, Heating decolorization, After filtration, the filtrate was cooled to 10 ° C for 20 hours, centrifuged, washed and dried to give 3-bromo-1,3,4,5-tetrahydro-2H-1-benzazepan-2-one. The purity of the product was 3, 10-bromo-1,3,4,5-tetrahydro-2H-1-benzazepan-2-one as high as 99.6% and the yield was as high as 98%.

Synthesis

According to the synthetic method, gamma-butyrolactone and benzene are taken as starting raw materials, and 3-bromo-1,3,4,5-tetrahydro-2H-1-benzoazepin-2-one is obtained through cyclization reaction, bromination reaction, oxime forming reaction and Beckmann rearrangement reaction respectively.