Dimethylformamide → HCID 12914969, compound

Temperature

-20 °C

Diisopropylamine (17.5 ml, 124.38 mmol) was introduced into THF (100 ml) under nitrogen. N-Butyllithium solution in hexane (15% strength, 75.9 ml, 124.38 mmol) was added dropwise at −78° C. The mixture was subsequently stirred for 45 minutes at −20° C. and then cooled again to −78° C. At this temperature, a solution of 1-methylpyrrole-2-carbonitrile (12 g, 113.07 mmol) in THF (50 ml) was added dropwise. After stirring for 45 minutes at −78° C., DMF (43.9 ml, 546.46 mmol) was added dropwise, and the mixture was stirred at this temperature for a further 2 hours. After addition of citric acid monohydrate (20.56 g), the mixture was warmed to room temperature, and water (112 ml) was added. The THF was removed in a rotary evaporator, and the aqueous phase was saturated with sodium chloride and extracted with diethyl ether (3×200 ml). The combined organic phases were washed with saturated sodium chloride solution and dried over sodium sulfate. The solvent was removed in a rotary evaporator and the crude product was purified by means of flash chromatography (silica gel, dichloromethane). Yield: 8.25 g (54%).

1. temperaturecooled again to −78° C
2. stirringAfter stirring for 45 minutes at −78° C.
3. stirringthe mixture was stirred at this temperature for a further 2 hours
4. temperaturethe mixture was warmed to room temperature
5. customThe THF was removed in a rotary evaporator
6. extractionextracted with diethyl ether (3×200 ml)
7. washThe combined organic phases were washed with saturated sodium chloride solution
8. dry with materialdried over sodium sulfate
9. customThe solvent was removed in a rotary evaporator
10. customthe crude product was purified by means of flash chromatography (silica gel, dichloromethane)

ORD record

ord-00b74858415443fea550a731264e2ba3

Source dataset

uspto-grants-2004_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06740647B1