Chloroform → HCID 70284007, compound

Participants

Reaction Steps

NMR analysis of both gums indicated the second to be of higher purity, so this was used in the subsequent stages. A mixture of the crude 1-(4-methoxyphenylsulphinyl)-4-phenoxybut-2-yne (2.1 g) and chloroform (25 ml) was heated under nitrogen at an external temperature of 80°-85° C. for 1 hour, allowed to stand at ambient temperature for 18 hours, and heated at an external temperature of 90°-95° C. for 6 hours. The solvent was removed by distillation to leave crude 5-methoxy-3-methylene-2-phenoxymethyl-2,3-dihydrobenzo[b]thiophen-2-ol as an orange gum. The orange gum was dissolved in dichloromethane (30 ml) and the solution was shaken vigorously for a few seconds with 5M aqueous sodium hydroxide solution (25 ml), then the organic solution was separated, washed with water (25 ml), dried (MgSO4), and the solvent removed in vacuo to leave crude 1-(5-methoxy-2,3-dihydrobenzo[b]thiophen-3-yl)-2-phenoxyethanone as a red gum (1.94 g) which was used without purification.

Provenance & Evidence