Formaldehyde → Methyl 1-methylpyrrolidine-2-carboxylate

Methyl pyrrolidine-2-carboxylate 10b crude product (5 g) was dissolved in 100 mL of methanol. The solution was cooled to 0˜5° C. in an ice-water bath, followed by addition of 13 mL of 40% formaldehyde. The reaction mixture was warmed up to room temperature and stirred for 2 hours, then cooled to 0˜5° C. in an ice-water bath, and sodium cyanoborohydride (5.45 g, 87.20 mmol) was added in batches. The reaction mixture was warmed up to room temperature and stirred for 24 hours. The mixture was concentrated under reduced pressure and added with 5 mL of water, extracted with dichloromethane (5 mL×3). The combined organic extracts were dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to obtain methyl 1-methylpyrrolidine-2-carboxylate 10c (4.7 g, yield 70.1) crude product as a brown oil.

1. temperatureThe solution was cooled to 0˜5° C. in an ice-water bath
2. temperaturecooled to 0˜5° C. in an ice-water bath
3. temperatureThe reaction mixture was warmed up to room temperature
4. stirringstirred for 24 hours
5. concentrationThe mixture was concentrated under reduced pressure
6. additionadded with 5 mL of water
7. extractionextracted with dichloromethane (5 mL×3)
8. dry with materialThe combined organic extracts were dried over anhydrous sodium sulfate
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure

ORD record

ord-ad7b6aed354a4a628bdc7e245218c1ba

Source dataset

uspto-grants-2014_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08901140B2