Thionyl Chloride → HCID 9983374, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 7,8-dimethoxy-2,3-dihydro-1-benzoxepin-4-carboxylic acid (0.5 g) dissolved in toluene (10 ml) is added thionyl chloride (1.5 ml), followed by stirring for one hour at 100° C. The reaction mixture is concentrated under reduced pressure to give a crude acid chloride, which is dissolved in methylene chloride (8 ml). The solution is added dropwise, while stirring under ice-cooling, to a solution of 1-(3,4,5-trimethoxybenzyl)piperazine (0.78 g) in a mixture of methylene chloride (20 ml) and triethylamine (1.6 ml), followed by stirring for 3 hours. The reaction mixture is poured into ice-water, followed by extraction with methylene chloride. The organic layer is washed with water, dried, and concentrated under reduced pressure. The residue is purified by means of a silica gel column chromatography (eluent: hexane-acetone-ethanol=10:8:1) to afford 1-(7,8-dimethoxy-2,3-dihydro-1-benzoxepin-4-carbonyl)-4-(3,4,5-trimethoxybenzyl)piperazine as a colorless oily product (0.9 g). This product is converted into its hydrochloride, followed by recrystallization from ethanol-ether to give colorless needles, m.p. 208°-210° C.

Provenance & Evidence