反应详情

2-Nitro-4-trifluoromethylbenzoyl chloride (4 g) was added at 0°-5° C. to a stirred solution of triethylamine (2.2 ml) and 6-methyltetrahydropyran-2,4-dione (2 g) in dry acetonitrile (25 ml) and the mixture was stirred at ambient temperature for 4 hours. Triethylamine (6.4 ml) and acetone cyanohydrin (0.3 ml) were added successively to the solution and the mixture stirred at ambient temperature for a further 2 hours. The mixture was diluted with dichloromethane (50 ml) and washed successively with 2N hydrochloric acid (20 ml) and water (3×20 ml). The dichloromethane solution was dried over sodium sulphate and evaporated under reduced pressure to give a brown gum which was triturated with a mixture of chloroform and hexane (1:1, 20 ml) to give 3-(2-nitro-4-trifluoromethylbenzoyl)-6-methyltetrahydropyran-2,4-dione (2.2 g), mp 135°-136.5° C., as a light cream crystalline solid.

1. stirringthe mixture stirred at ambient temperature for a further 2 hours
2. washwashed successively with 2N hydrochloric acid (20 ml) and water (3×20 ml)
3. dry with materialThe dichloromethane solution was dried over sodium sulphate
4. customevaporated under reduced pressure
5. customto give a brown gum which
6. customwas triturated with a mixture of chloroform and hexane (1:1, 20 ml)