反应详情

To a solution of 3 g of 1,5-dihydro-5-n-propyloxy-2H-pyrrol-2-one, in 80 cm3 of tetrahydrofuran, cooled to -45° C., there is added 13.25 cm3 of a 1.6M solution of N-butyllithium in n-hexane, while maintaining the temperature between -35° and -45° C. After 30 minutes, a solution of 3.74 g of benzenesulphonyl chloride in 12 cm3 of tetrahydrofuran is added at a temperature between -45° and -35° C., then the temperature is allowed to return to the ambient over two hours, followed by evaporating to dryness and chromatographing on silica (eluent: ethyl acetate-n-hexane, 1--1). 2.2 g of the expected product is recovered. m.p. 56°-58° C., crystallized from a mixture of ethyl ether-n-hexane, 1-2. By crystallizing from isopropanol, 1.4 g of the expected product is obtained, m.p. 66°-67° C.

1. temperaturewhile maintaining the temperature between -35° and -45° C
2. waitto return to the ambient over two hours
3. customby evaporating to dryness and chromatographing on silica (eluent: ethyl acetate-n-hexane, 1--1)
4. custom2.2 g of the expected product is recovered
5. customm.p. 56°-58° C., crystallized from a mixture of ethyl ether-n-hexane, 1-2
6. customBy crystallizing from isopropanol