1-benzothien-7-ylmethanol synthesis

Steps:

92.3

(3) Benzo[b]thiophen-7-ylmethanol Lithium aluminum hydride (300 mg) was suspended in tetrahydrofuran (20 mL) in a nitrogen atmosphere. A solution of methyl benzo[b]thiophene-7-carboxylate (1.5 g) in tetrahydrofuran (10 mL) was added under ice-cooling, and the mixture was stirred under ice-cooling for 40 minutes. 1 M hydrochloric acid was added dropwise to the reaction mixture under ice-cooling, followed by extraction with ethyl acetate. The organic layer was sequentially washed with water and a saturated sodium chloride solution, dried over magnesium sulfate and filtered. Then, the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (heptane-ethyl acetate) to obtain the title compound (1.22 g). ¹H-NMR (400 MHz, CDCl₃) δ (ppm) : 1.89 (t, J=6.0 Hz, 1H), 4.98 (t, J=6.0 Hz, 2H), 7.33-7.39 (m, 3H), 7.46 (d, J=5.6 Hz, 1H), 7.75-7.80 (m, 1H).

References:

EP2017275,2009,A1 Location in patent:Page/Page column 151