Dichloromethane → 1-(1-Benzothiophen-3-yl)ethan-1-ol

Participants

Reaction Steps

A solution of methyl benzo[b]thiophen-3-ylacetate (69 g) in dry tetrahydrofuran (100 ml) was added dropwise to a suspension of lithium aluminium hydride (10 g) in dry tetrahydrofuran (500 ml) at room temperature followed by reflux for 1 h. Hydrolysis with water, filtration and removal of solvent gave an oil which was applied to a silica gel column (eluent:methylene chloride) giving 34.5 g of benzo[b]thiophen-3-ylethanol as an oil. The product was dissolved in 200 ml of methylene chloride, thionyl chloride (20 ml) was added followed by reflux for 5 h. Removal of solvent and excess thionyl chloride in vacuo gave 3-(2-chloro-1-ethyl)-benzo[b]thiophene as an oil (45 g). The chloride was converted to 4-benzo[b]thiophen-3-yl-1-butanol via treatment with dimethyl malonate followed by hydrolysis, decarboxylation and reduction according to the method described in EXAMPLE 11. The title compound 10a was prepared from 4-benzo[b]thiophen-3-yl-1-butanol and spiro[isobenzofuran-1(3H),4'-piperidine] by the method described in EXAMPLE 2. Yield: 2.2 g, mp: 144°-45° C.

Provenance & Evidence