Allylamine → 6-(trifluoromethyl)-3,4-dihydro-N-(2-propenyl)-2H-1,4-benzoxazine-2-carboxamide

Participants

Reaction Steps

A mixture of 20.6 g of 6C, 25.7 g of 2-propenamine and 34 ml of ethanol was stirred at room temperature for 36 hours. The excess amine and solvent were evaporated under reduced pressure. The solid residue was mixed with 150 ml of ether and the remaining solid material was filtered. The filtrate was added to petroleum ether and cooled; the resulting viscous material was filtered. The filtrate was stripped and the residue was triturated with petroleum ether to give an off-white powder which was purified by dry-column chromatography (silica gel), using ether as eluent. The higher Rf band was collected and extracted with ether, the solvent was stripped and the solid residue was recrystallized from ether/hexane (4/5 v/v). Thin-layer chromatography indicated that two components were present. The product was purified by wet-column chromatography (silica gel) using petroleum ether/ethyl ether (1:4 v/v) as eluent. The solvent was stripped and the residue was recrystallized from ether/hexane (75:100 v/v) to give 6, as a solid, mp: 95°-97° C.

Provenance & Evidence