Diisopropylamine → 6-Methoxybenzo[B]thiophen-3(2H)-one

Temperature

-78 °C

n-BuLi (1.6 M in hexanes, 13 mL, 20.8 mmol) was added slowly to a solution of diisopropylamine (2.91 mL, 20.8 mmol) in THF at −78° C. The mixture was stirred under nitrogen for 30 min and N,N-diethyl-4-methoxy-2-(methylthio)benzamide (2.4 g, 9.47 mmol), dissolved in 10 mL of anhydrous THF was added to the reaction dropwise. Stirring was continued at −78° C. for 1 h and the cooling bath was removed. After 12 h, the reaction was cooled back down to −78° C. and a 1:1 mixture of methanol and acetic acid (10 mL) was added to the mixture. The reaction was stirred for 15 min and the cooling bath was removed and allowed to warm up to room temperature. The reaction was diluted with ethyl acetate and the organic layer was washed with saturated aqueous sodium bicarbonate, water and brine. The organic layer was then dried with sodium sulfate, concentrated and purified by flash chromatography using a gradient of 15 to 40% ethyl acetate in hexanes to obtain an off white solid. Yield=1.4 g. MS (M−H)-179.

1. additionwas added to the reaction dropwise
2. stirringStirring
3. waitwas continued at −78° C. for 1 h
4. customthe cooling bath was removed
5. waitAfter 12 h
6. additiona 1:1 mixture of methanol and acetic acid (10 mL)
7. additionwas added to the mixture
8. stirringThe reaction was stirred for 15 min
9. customthe cooling bath was removed
10. temperatureto warm up to room temperature
11. additionThe reaction was diluted with ethyl acetate
12. washthe organic layer was washed with saturated aqueous sodium bicarbonate, water and brine
13. dry with materialThe organic layer was then dried with sodium sulfate
14. concentrationconcentrated
15. custompurified by flash chromatography
16. customto obtain an off white solid

ORD record

ord-e14a89f540914083af654924ed783bb5

Source dataset

uspto-grants-2010_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07858785B2