[BH4-].[Na+].[Cl:3][C:4]1[CH:12]=[C:11]2[C:7](/[C:8](=[CH:14]/[C:15]3[CH:20]=[CH:19][C:18]([Cl:21])=[CH:17][CH:16]=3)/[C:9](=[O:13])[NH:10]2)=[CH:6][CH:5]=1.O>CO.CS(C)=O>[Cl:3][C:4]1[CH:12]=[C:11]2[C:7]([CH:8]([CH2:14][C:15]3[CH:16]=[CH:17][C:18]([Cl:21])=[CH:19][CH:20]=3)[C:9](=[O:13])[NH:10]2)=[CH:6][CH:5]=1
Sodium borohydride (3.0 g, 79 mmol) (Aldrich) was added in small portions to a suspension of 6-chloro-3-(4-chloro-benzylidene)-1,3-dihydro-indol-2-one (19 g, 66 mmol) (from example 76a supra) in methanol (200 mL) and DMSO (50 mL) at such a rate that gas evolution was not too vigorous. When the addition was complete, mixture was stirred at room temperature for 0.5 h-1 h. After water (200 mL) was added, the resulting precipitate was collected and dried to give 18.3 g of rac-6-chloro-3-(4-chloro-benzyl)-1,3-dihydro-indol-2-one as a light yellow solid. MS: 293 (M+H)+.
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