Methanol → HCID 66936493, compound

To a solution of 1,1-dimethylethyl 2-methyl-3-oxo-1-pyrazolidinecarboxylate (0.98 g, 4.89 mmol) in dry dichloromethane was added borane dimethyl sulfide complex (1.16 ml, 12.24 mmol). The mixture was stirred at rt overnight. LCMS indicated ˜40% starting material left. Another portion of borane dimethyl sulfide complex (0.5 ml, 5.28 mmol) was added, and stirring continued overnight. Methanol was added dropwise to the reaction mixture until bubbling ceased. Water (1 ml) was then added, and the mixture was refluxed for 1 h. After cooling to rt, the mixture was concentrated to dryness under vacuum. The residue was taken up in water (30 ml) and dichloromethane (45 ml), the organic layer was separated, and the aqueous layer was extracted with dichloromethane (45 ml). The combined organic solution was dried (Na2SO4), filtered and concentrated to provide 1,1-dimethylethyl 2-methyl-1-pyrazolidinecarboxylate (0.48 g, 52.7%). LCMS: (2M+H)+ 372.9.

1. waitleft
2. additionAnother portion of borane dimethyl sulfide complex (0.5 ml, 5.28 mmol) was added
3. stirringstirring continued overnight
4. customuntil bubbling
5. additionWater (1 ml) was then added
6. temperaturethe mixture was refluxed for 1 h
7. temperatureAfter cooling to rt
8. concentrationthe mixture was concentrated to dryness under vacuum
9. customdichloromethane (45 ml), the organic layer was separated
10. extractionthe aqueous layer was extracted with dichloromethane (45 ml)
11. dry with materialThe combined organic solution was dried (Na2SO4)
12. filtrationfiltered
13. concentrationconcentrated

ORD record

ord-eae2b4ff751f4a52815e28432b4796ef

Source dataset

uspto-grants-2011_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07893056B2