反应详情

70% tert-Butyl hydroperoxide solution (111 ml, 0.81 mol) was added during 3 minutes to a stirred suspension of chromium (VI) oxide (0.59 g, 5.9 mmol) in dichloromethane (232 ml) in a flask fitted with a reflux condenser, whilst cooling the mixture in a bath of water at room temperature. 2-Methyl-3-pivaloyloxymethyl-3,4,7,8-tetrahydro-6H-cyclopenta[g]quinazolin-4-one (36.586 g, 0.116 mol), prepared as described in Example 1(5), was added in portions during 2 minutes and the mixture was stirred at ambient temperature for 16 hours. It was then cooled to 0° C. and 10% aqueous sodium metabisulphite solution (195 ml) was added at such a rate that the temperature did not exceed 10° C. The resulting mixture was allowed to warm to room temperature and stirred for 21/2 hours. It was then partitioned between ethyl acetate (400 ml) and half-saturated brine (300 ml). The aqueous layer was extracted with ethyl acetate (2×150 ml) and the combined organic solution was washed successively with saturated aqueous sodium hydrogen carbonate (300 ml), saturated brine (2×150 ml), saturated aqueous sodium hydrogen carbonate (150 ml) and saturated brine (150 ml), then dried (MgSO4), treated with charcoal powder and evaporated to dryness. A portion of ethyl acetate was added and evaporated and the residue was crystallised from hexane-ethyl acetate to give 2-methyl-3-pivaloyloxymethyl-3,4,7,8-tetrahydro-6H-cyclopenta[g]-quinazolin-4,6-dione (10.371 g, 27%), m.p. 203°-205° C.

1. customfitted with a reflux condenser
2. additionwas added in portions during 2 minutes
3. temperatureIt was then cooled to 0° C.
4. customdid not exceed 10° C
5. temperatureto warm to room temperature
6. stirringstirred for 21/2 hours
7. customIt was then partitioned between ethyl acetate (400 ml) and half-saturated brine (300 ml)
8. extractionThe aqueous layer was extracted with ethyl acetate (2×150 ml)
9. washthe combined organic solution was washed successively with saturated aqueous sodium hydrogen carbonate (300 ml), saturated brine (2×150 ml), saturated aqueous sodium hydrogen carbonate (150 ml) and saturated brine (150 ml)
10. dry with materialdried (MgSO4)
11. additiontreated with charcoal powder
12. customevaporated to dryness
13. additionA portion of ethyl acetate was added
14. customevaporated
15. customthe residue was crystallised from hexane-ethyl acetate