反应详情

In a three necked one liter flask fitted with a thermometer, a dropping funnel and a magnetic stirrer were placed 173 g. (0.9 mole) of benzyl acetoacetate [The benzyl acetoacetate was prepared as described by Baker et al., J. Org. Chem. 17, 91 (1952)] and 130 ml. of glacial acetic acid. The contents were cooled in an ice bath and a solution of 69 g. (1 mole) of sodium nitrite in 130 ml. of water was added over a period of half an hour; the temperature was kept at 0° to 10° C. After the reaction mixture was stirred for one hour at room temperature, 400 ml. of water was added and the stirring was continued for an additional two hours. The reaction mixture was extracted three times with 200 ml. portions of diethyl ether. The diethyl ether extracts were combined, washed once with water, three times with saturated sodium bicarbonate solution and once with brine. After drying over anhydrous sodium sulfate, the diethyl ether solution was evaporated leaving [1.1] as a clear oil which solidified upon trituration with petroleum ether (30°-60°) to give 186.5 g. (93.2%) of white solid. Its NMR spectrum was consistent with the assigned structure. Generally the product was used as such in subsequent reaction but it can be recrystallized from toluene, m.p. 81°-82° C.

1. customIn a three necked one liter flask fitted with a thermometer, a dropping funnel and a magnetic stirrer
2. temperatureThe contents were cooled in an ice bath
3. customwas kept at 0° to 10° C
4. waitthe stirring was continued for an additional two hours
5. extractionThe reaction mixture was extracted three times with 200 ml
6. washwashed once with water, three times with saturated sodium bicarbonate solution and once with brine
7. dry with materialAfter drying over anhydrous sodium sulfate
8. customthe diethyl ether solution was evaporated