Benzenesulfonyl chloride → 1-benzenesulphonyl-1,5-dihydro-5-n-propyloxy-2H-pyrrol-2-one
Reaction equation
[CH2:1]([O:4][CH:5]1[NH:9][C:8](=[O:10])[CH:7]=[CH:6]1)[CH2:2][CH3:3].[Li+].CCC[CH2-].[C:16]1([S:22](Cl)(=[O:24])=[O:23])[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1>O1CCCC1.CCCCCC>[C:16]1([S:22]([N:9]2[CH:5]([O:4][CH2:1][CH2:2][CH3:3])[CH:6]=[CH:7][C:8]2=[O:10])(=[O:24])=[O:23])[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 2
Procedure
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.
Workup
- temperaturewhile maintaining the temperature between -35° and -45° C
- waitto return to the ambient over two hours
- customby evaporating to dryness and chromatographing on silica (eluent: ethyl acetate-n-hexane, 1--1)
- custom2.2 g of the expected product is recovered
- customm.p. 56°-58° C., crystallized from a mixture of ethyl ether-n-hexane, 1-2
- customBy crystallizing from isopropanol
Sources & evidence
- ORD record
- ord-1235511736e6492ab8fb32385faeef0c
- Source dataset
- uspto-grants-1989_12
- Patent number
- US04885307
Reaction notes
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