Hydrochloric Acid → HCID 15379729, compound

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Reaction Steps

2.3 g (7.5 mmol) of the carboxylic acid 26b are dissolved in 40 ml of absolute THF and, at −20° C., admixed successively with 1.2 g (12 mmol) of N-methylmorpholine and 1.1 g (7.5 mmol) of isobutyl chloroformate. After 30 min, the mixture is admixed with 3.9 g (37.5 mmol) of O-trimethylsilylhydroxylamine and stirred at RT for a further 5 h. 200 ml of water are added and the mixture is acidified with dilute HCl and extracted repeatedly with dichloromethane. The pooled organic phases are dried over Na2SO4 and concentrated under reduced pressure. The resulting oil is chromatographed under pressure over silica gel 60 using ethyl acetate/dichloromethane (1:1) as mobile phase. Recrystallization of the product fractions from ethyl acetate gave crystalline hydroxamic acid 26c. Yield: 1.4 9 (55% of theory) Melting point: 164-165° C. (decomposition).

Provenance & Evidence