Triethylamine → 6-chloro-3,4-dihydro-3-oxo-N-[1-(3-phenoxypropyl)-4-piperidyl]-2H-1,4-benzoxazine-8-carboxamide hydrochloride

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Reaction Steps

A solution of 2.3 g of 6-chloro-3,4-dihydro-3-oxo-2H-1,4-benzoxazine-8-carboxylic acid in 100 ml of tetrahydrofuran is cooled to below 0° C. and 2 ml of triethylamine is added under stirring thereto. Further, 1.1 g of ethyl chlorocarbonate is added and the mixture is stirred for 3 hours. To the resultant mixture is added 2.5 g of 4-amino-1-(3-phenoxypropyl)piperidine and the mixture stirred for 8 hours followed by collecting by filtration and washing with tetrahydrofuran and water. To a suspension of thus obtained crystals in 100 ml of methanol are added 10 ml of 10% hydrochloric acid and 30 ml of water and then the suspension is stirred. The collection of the crystals by filtration gives 6-chloro-3,4-dihydro-3-oxo-N-[1-(3-phenoxypropyl)-4-piperidyl]-2H-1,4 -benzoxazine-8-carboxamide hydrochloride, melting at 290°-300° C. with decomposition.

Provenance & Evidence