Hydroxylamine → Oxametacin

Participants

Reaction Steps

In a four-necked flask equipped with a mechanical stirrer, a dropping funnel, a cooler with CaCl2 tube and thermometer, there was poured a solution of 230 g (0.637 mole) of 1-(4-chloro-benzoyl)-5-methoxy-2-methyl-3-indolyl-acetic acid and 88.2 ml (0.637 mole) of triethylamine in 400 ml of chloroform. This solution was added dropwise with stirring to a solution of 60.7 ml (0.637 mole) of ethyl chlorocarbonate, keeping the temperature low by an external cooling of ice and water. The formed triethylamine hydrochloride was removed by filtration, then the chloroform solution was added at room temperature to 21.12 g (0.64 mole) of hydroxylamine. After stirring for some hours, the formed precipitate was recovered by filtration, washed with chloroform, dried and subsequently washed several times with water in order to remove the inorganic residues. After drying in oven, 210 g (yield 91% by weight) of pure oxamethacin were obtained. M.p. 181°-83° C.

Provenance & Evidence