Pyridine → N-nitroso-N-(tert-butoxycarbonyl)amino-cyclopropane

Temperature

0 °C

A solution of cyclopropyl-carbamic acid tert-butyl ester (4.8 g, 30.5 mmol) and pyridine (5.9 mL, 73 mmol) in acetonitrile (75 mL) was cooled to approximately −25° C. in a carbon tetrachloride/dry ice bath. Nitrosonium tetrafluoroborate (4.7 g, 40.2 mmol) was added over a period of 20 min. The cooling bath was removed and the reaction mixture was stirred in an ice-bath at 0° C. for 2.5 h. Water (100 mL) and ethyl acetate (500 mL) were added and the organic layer was washed with water (100 mL), 2 M aqueous HCl (50 mL) and brine (100 mL), dried (magnesium sulfate), filtered, evaporated, and purified in two batches using an ISCO 120 g column, eluting with 10-30% ethyl acetate, to give N-nitroso-N-cyclopropyl-carbamic acid tert-butyl ester (1.5 g, 26%) as a yellow oil.

1. customThe cooling bath was removed
2. additionWater (100 mL) and ethyl acetate (500 mL) were added
3. washthe organic layer was washed with water (100 mL), 2 M aqueous HCl (50 mL) and brine (100 mL)
4. dry with materialdried (magnesium sulfate)
5. filtrationfiltered
6. customevaporated
7. custompurified in two batches
8. washeluting with 10-30% ethyl acetate

ORD record

ord-4a543066752343ce8ec6087e3ce4aff7

Source dataset

uspto-grants-2009_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07622492B2