反应 #95624

反应方程式

ethyl 8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate

lithium borohydride

water

hydrochloric acid water

→

8-fluoro-4,5-dihydro-3-(hydroxymethyl)-5-methyl-6H-imidazo[ 1,5-a][1,4]benzodiazepin-6-one

溶剂

tetrahydrofuran

tetrahydrofuran

反应条件

后处理

1. 1
   workup.STIRRINGstirred at room temperature overnight
2. 2
   其他After removal of the tetrahydrofuran in vacuo
3. 3
   workup.ADDITIONthe residue is treated with 14 ml of concentrated ammonia
4. 4
   workup.WAITThe mixture is left
5. 5
   其他to crystallise in the cold and
6. 6
   其他separated material
7. 7
   过滤is filtered off under suction
8. 8
   洗涤washed with water
9. 9
   其他After recrystallisation from ethanol

实验过程

15.0 g (49.5 mmol) of ethyl 8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate are dissolved under argon in 450 ml of boiling absolute tetrahydrofuran (filtered over Alox) and added dropwise at 50° C. to a solution of 1.1 g (49.5 mmol) of lithium borohydride in 50 ml of absolute tetrahydrofuran. The mixture is stirred at 40° C. for 4 hours and at the boiling point for 2.5 hours. Subsequently, the mixture is decomposed at 40° C. with 20 ml of water and 20 ml of concentrated hydrochloric acid/water (1:1) and stirred at room temperature overnight. After removal of the tetrahydrofuran in vacuo, the residue is treated with 14 ml of concentrated ammonia. The mixture is left to crystallise in the cold and separated material is filtered off under suction and washed with water. After recrystallisation from ethanol, there is obtained 8-fluoro-4,5-dihydro-3-(hydroxymethyl)-5-methyl-6H-imidazo[ 1,5-a][1,4]benzodiazepin-6-one of melting point 221°-223° C.

来源