Thieno(2,3-b)pyridine-2-carbaldehyde → Thieno[2,3-b]pyridin-2-ylmethanol

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Reaction Steps

Thieno[2,3-b]pyridine-2-carboxaldehyde (1.63 g) prepared according to J. Het. Chem. 355 (1974) was dissolved in ethanol (20 ml) and to the solution was added sodium borohydride (0.19 g). After 30 minutes the solution was evaporated to dryness and the residue extracted with methylene chloride (50 ml). The organic extract was washed with water (2×25 ml), the extract dried and then evaporated to obtain 2-hydroxymethylthieno[2,3-b]pyridine (1.40 g) as an amber oil. 'HNMR (CDCl3,60 MHz): 4.9 (s, 1H), 6.3 (s, 1H), 6.9 s, 1H), 7.1 (m, 1H), 7.8 (m, 1H), 8.4 (m, 1H). This product was dissolved in a solution of pyridine (2 ml) in methylene chloride (20 ml) and to the resulting solution was added methane sulfonyl chloride (1.14 g). Upon stirring overnight at room temperature, the solution was poured onto ice water (25 ml). The methylene chloride layer was separated, washed with water (2×10 ml) and then dried and evaporated. The residue was purified by chromatography on silica gel with a mixture of methylene chloride-ethyl acetate (9:1) as eluant to obtain the title compound (0.76 g; m.p. 47°-49° C.).

Provenance & Evidence