Water → HCID 19973447, compound

Participants

Reaction Steps

A suspension of 56.89 g (202 mmol) of the N-methyl-1-(4-nitroimidazol-1-yl)-2-oxocyclohexanecarbothioamide prepared in the Example 16 in 640 ml of methanol was cooled with ice. 2.68 g (70.8 mmol) of sodium borohydride was added to the resulting suspension in portions in 3 minutes in such a way that the bulk temperature did not exceed 10° C. The obtained mixture was stirred under cooling with ice for 30 minutes, followed by the addition of a saturated aqueous solution of ammonium chloride and water in this order. The obtained mixture was extracted with ethyl acetate. The organic phase was washed with a saturated aqueous solution of common salt and dried over anhydrous magnesium sulfate. The resulting organic phase was analyzed by silica gel thin-layer chromatography [developer: benzene/ethyl acetate (1:2)], by which it was ascertained that the product of this stage was composed of a lowly polar diastereomer (L form. Rf: 0.41) and a highly polar diastereomer (M form. RF: 0.29) at a ratio of 2:1. The organic phase was concentrated. In the course of this concentration, a crystal began to precipitate. The crystal thus formed was recovered by filtration. Thus, 28.48 g of the title compound was obtained in the form of a diastereomer as a pale-yellow crystal (yield: 50%).

Provenance & Evidence