Formaldehyde → HCID 13663046, compound

Participants

Reaction Steps

A solution of n-butyl-lithium in hexane (13.2 ml of 1.55 M solution) was added dropwise to a stirred solution of 2.6-dibromo-3-methylbenzo[b]thiophene (6.60 g) in dry ether (150 ml) at 0° under dry nitrogen and the mixture was stirred at 0° for 30 minutes. Paraformaldehyde (0.71 g) was then added portionwise and the mixture was stirred at 0° for 3 hours. Water was added and the layers were separated. The ether layer was washed with water, dried (Na2SO4) and evaporated to give an oil which was chromatographed on silica gel. Elution with chloroform first gave some impurity followed by pure product. Evaporation of the product-containing fractions gave a solid which was crystallised from ethyl acetate/petrol (b.p. 60°-80°) to give 6-bromo-2-hydroxymethyl-3-methylbenzo[b]thiophene (3.20 g), m.p. 95°-96°.

Provenance & Evidence