Tert-butyl 4-(methoxy(methyl)carbamoyl)-3-methylisothiazol-5-ylcarbamate → Tert-butyl 4-(4-chlorobenzoyl)-3-methylisothiazol-5-ylcarbamate
Reaction equation
CON(C)[C:4]([C:6]1[C:7]([CH3:19])=[N:8][S:9][C:10]=1[NH:11][C:12](=[O:18])[O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:5].[Cl:21][C:22]1[CH:27]=[CH:26][C:25]([Mg]Br)=[CH:24][CH:23]=1>C1COCC1>[Cl:21][C:22]1[CH:27]=[CH:26][C:25]([C:4]([C:6]2[C:7]([CH3:19])=[N:8][S:9][C:10]=2[NH:11][C:12](=[O:18])[O:13][C:14]([CH3:15])([CH3:16])[CH3:17])=[O:5])=[CH:24][CH:23]=1Participants
4
Procedure
To a solution of tert-butyl 4-(methoxy(methyl)carbamoyl)-3-methylisothiazol-5-ylcarbamate (1.20 g, 3.98 mmol) in THF (30 mL) at −10° C. was added a solution of (4-chlorophenyl)magnesium bromide (1 M in diethylether) (11.95 mL, 11.95 mmol). After a period of 15 min, additional Grignard reagent was added (11.95 mL). After a period of 30 min, the reaction mixture was quenched with saturated ammonium chloride and EtOAc. The organic phase was separated, dried over Na2SO4, filtered and evaporated under reduced pressure. The resulting mixture was purified by flash chromatography (EtOAc/hexane 0:10 to 4:6) to give tert-butyl 4-(4-chlorobenzoyl)-3-methylisothiazol-5-ylcarbamate as an oil (1.1 g). LRMS (M+H)+: 353 m/z.