Phenyl chloroformate → 1-Benzenesulfonyl-3-(1-phenoxycarbonyl4-piperazinyl)-1H-indazole
Reaction equation
[C:1]1([S:7]([N:10]2[C:18]3[C:13](=[CH:14][CH:15]=[CH:16][CH:17]=3)[C:12]([N:19]3[CH2:24][CH2:23][N:22](C)[CH2:21][CH2:20]3)=[N:11]2)(=[O:9])=[O:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.Cl[C:27]([O:29][C:30]1[CH:35]=[CH:34][CH:33]=[CH:32][CH:31]=1)=[O:28]>ClCCl>[C:1]1([S:7]([N:10]2[C:18]3[C:13](=[CH:14][CH:15]=[CH:16][CH:17]=3)[C:12]([N:19]3[CH2:24][CH2:23][N:22]([C:27]([O:29][C:30]4[CH:35]=[CH:34][CH:33]=[CH:32][CH:31]=4)=[O:28])[CH2:21][CH2:20]3)=[N:11]2)(=[O:9])=[O:8])[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1Participants
4
Procedure
To a solution of 1-benzenesulfonyl-3-(1-methyl-4-piperazinyl)-1H-indazole (2.1 g, 5.89 mmol) in dichloromethane (100 ml) was added phenyl chloroformate (3.8 ml, 29.45 mmol) at room temperature. The reaction mixture was warmed to reflux for 2 hours, cooled to room temperature, and concentrated. The residue was diluted with ethyl acetate, filtered and purified via flash column chromatography (silica gel, ethyl acetate). Concentration of the product containing fractions gave an oil which solidified on standing. The product was washed well with heptane to give 1.5 g of a white solid, m.p. 112°-114° C.