Tetrahydrofuran → HCID 86688838, compound

Temperature

-78 °C

To a solution of 4-hexyl-4H-dithieno[3,2-b;2′,3′-d]pyrrole (36) (1.100 g, 4.18 mmol) in 126 ml of dry THF are added, at −78° C. under argon over a period of 20 minutes, n-BuLi (1.6 M in hexanes; 5.5 ml, 8.79 mmol). After the addition, the mixture was stirred at −78° C. for a further 90 minutes and then warmed to room temperature. After stirring at RT for a further 1 hour, the mixture was cooled again to −78° C. and N-formylpiperidine (1.045 g, 9.24 mmol) was added rapidly by means of a syringe. The mixture was stirred at −78° C. for a further 30 minutes and then brought to RT within 4 hours. Stirring under argon continued overnight. The reaction was stopped by adding a saturated NH4Cl solution (47 ml). After continuing to stir at RT for 15 minutes, the mixture was transferred to a separating funnel and extracted with dichloromethane (3×80 ml). The combined organic phases were washed with water (2×30 ml) and dried over Na2SO4. After filtration and removal of the solvent, the crude product was purified by means of flash chromatography (silica gel, DCM as eluent, Rf=0.25). After the product fractions had been combined and the solvent had been removed, a yellow solid was isolated (533 mg, 1.67 mmol; 40%). 1H NMR (CDCl2); δ=9.88 (s, 2H, CHO), 7.63 (s, 2H, Th—H), 4.21 (t, 2H, CH2), 1.85 (m, 2H, CH2), 1.12 (m, 6H, 3×CH2), 0.80 (t, 3H, CH3).

1. additionAfter the addition
2. temperaturewarmed to room temperature
3. stirringAfter stirring at RT for a further 1 hour
4. temperaturethe mixture was cooled again to −78° C.
5. stirringThe mixture was stirred at −78° C. for a further 30 minutes
6. waitbrought to RT within 4 hours
7. stirringStirring under argon
8. waitcontinued overnight
9. stirringto stir at RT for 15 minutes
10. customthe mixture was transferred to a separating funnel
11. extractionextracted with dichloromethane (3×80 ml)
12. washThe combined organic phases were washed with water (2×30 ml)
13. dry with materialdried over Na2SO4
14. filtrationAfter filtration and removal of the solvent
15. customthe crude product was purified by means of flash chromatography (silica gel, DCM as eluent, Rf=0.25)
16. customthe solvent had been removed
17. customa yellow solid was isolated (533 mg, 1.67 mmol; 40%)

ORD record

ord-579bc28746424414881217dd1683f8f7

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09127020B2