1,3-Dibromo-5,5-dimethylhydantoin → HCID 19915440, compound

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Reaction Steps

4.0 g (13.4 mmol) of 1-chloro-3-(2-chlorophenyl)-2-(4-fluorophenyl)-2-propanol are photobrominated with 2.3 g (8.0 mmol) of 1,3-dibromo-5,5-dimethylhydantoin in 80 ml of tetrachloromethane at 35° C. while stirring vigorously and irradiating with mixed light from an Osram HWL 235 V/500 W lamp. The hydantoin is filtered off with suction, the filtrate is extracted with dilute sodium carbonate solution and water, and conventional working up provides 5.1 g of crude product as an oil which is employed for the next stage. The erythro:threo isomer ratio found from the signals for the --CHBr--groups in the 1H-NMR spectrum, which appear at 6.4 ppm for the erythro compounds and at 6.2 ppm for the threo compound (each measured in CDCl3), is 4:1. The erythro isomer is also characterized by a doublet of doublets at 4.1 ppm.

Provenance & Evidence