Sodium borohydride → 6-Methoxy-1-benzothiophene

6-Methoxybenzo[b]thiophen-3(2H)-one (1.4 g, 7.76 mmol) was dissolved in a mixture of methanol (18 mL) and 2.5 M sodium hydroxide (3 mL). The mixture was treated with sodium borohydride (0.589 g, 15 mmol) in 10 mL of methanol and 3 mL of 2.5 M sodium hydroxide. The reflux was heated to reflux for 1 h and then at 60° C. overnight. The reaction was cooled down to room temperature and the methanol removed in vacuo. The remaining aqueous layer was acidified to pH 4 with 1 N hydrochloric acid. The aqueous layer was extracted with ethyl acetate and washed with 1 N HCl. The organic layer was further washed with water, saturated sodium bicarbonate, water and brine. The organic layer was dried with sodium sulfate, concentrated and purified by flash chromatography usng a gradient of 20 to 50% ethyl acetate in hexanes to afford a clear oil (0.843 g).

1. temperatureThe reflux was heated
2. temperatureto reflux for 1 h
3. customat 60° C.
4. customovernight
5. customthe methanol removed in vacuo
6. extractionThe aqueous layer was extracted with ethyl acetate
7. washwashed with 1 N HCl
8. washThe organic layer was further washed with water, saturated sodium bicarbonate, water and brine
9. dry with materialThe organic layer was dried with sodium sulfate
10. concentrationconcentrated
11. custompurified by flash chromatography

ORD record

ord-79b1d4e6ffc8444688f13ea1be1bc5af

Source dataset

uspto-grants-2010_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07786132B2