反应详情

A mixture of 33.2 g (0.1 mol) of diethyl (1,3,4,5-tetrahydro-4-methyl-5-oxo-2H-1,4-benzodiazepin-2-ylidene)malonate, 8.0 g (0.2 mol) of sodium hydroxide and 400 ml of absolute ethanol is heated to reflux for 3 hours. The mixture is subsequently left to crystallise at 0° C. and the separated solid material is filtered off under suction and transferred to a separating funnel. 100 ml of chloroform and 25 ml of water are added thereto. Then, the aqueous phase is separated. The organic phase is washed with 25 ml of water, dried over sodium sulphate and evaporated. There is obtained crystalline ethyl (1,3,4,5-tetrahydro-4-methyl-5-oxo-2H-1,4-benzodiazepin-2-ylidene)acetate of melting point 154°-155° C.

1. temperatureis heated
2. temperatureto reflux for 3 hours
3. waitThe mixture is subsequently left
4. customto crystallise at 0° C.
5. filtrationthe separated solid material is filtered off under suction
6. customtransferred to a separating funnel
7. addition100 ml of chloroform and 25 ml of water are added
8. customThen, the aqueous phase is separated
9. washThe organic phase is washed with 25 ml of water
10. dry with materialdried over sodium sulphate
11. customevaporated