Dimethylformamide → HCID 86714196, compound

Temperature

-78 °C

Naptho[2,3-b]thiophene (4, 4.00 g, 21.7 mmol., 1.00 equiv.) and THF (360 mL) were added to a 500 mL Schlenk flask. The mixture was cooled to −78° C. and n-butyllithium was added (2.5 M in hexanes, 9.6 mL, 24 mmol., 1.1 equiv.). The mixture was stirred at −78° C. for 15 minutes before removing the dry ice/acetone bath and stirring at ambient for 2 hours. The mixture was cooled back to −78° C. and N,N-dimethylformamide (2.0 mL, 26 mmol., 1.2 equiv.) was added. The mixture was left to warm slowly to room temperature while stirring for 16 hours. The solution was diluted with water (500 mL) and diethyl ether (500 mL). The layers were separated and the aqueous layer was extracted with diethyl ether (250 mL). The combined organic layers were washed with brine (300 mL), dried with MgSO4 and concentrated. The crude material was purified by silica gel column chromatography (solid loading, dichloromethane) to give a yellow solid (3.69 g, 80% yield). 1H NMR (400 MHz, CDCl3) δ ppm 10.18 (s, 1H), 8.52 (s, 1H), 8.39 (s, 1H), 8.16 (s, 1H), 8.07-7.88 (m, 2H), 7.54 (dddd, J=21.45, 8.05, 6.69, 1.28 Hz, 2H).

1. custombefore removing the dry ice/acetone bath
2. stirringstirring at ambient for 2 hours
3. temperatureThe mixture was cooled back to −78° C.
4. waitThe mixture was left
5. temperatureto warm slowly to room temperature
6. stirringwhile stirring for 16 hours
7. customThe layers were separated
8. extractionthe aqueous layer was extracted with diethyl ether (250 mL)
9. washThe combined organic layers were washed with brine (300 mL)
10. dry with materialdried with MgSO4
11. concentrationconcentrated
12. customThe crude material was purified by silica gel column chromatography (solid loading, dichloromethane)

ORD record

ord-b6140ba53c994e6bb78664672e913aae

Source dataset

uspto-grants-2016_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09312501B2