Acetic Anhydride → HCID 86636108, compound

Temperature

-15 °C

A mixture of boron trifluoride etherate (667 μL, 5.3 mmol) and 1,2-dimethoxyethane (2 mL) was cooled to −15° C. in an ice/acetonitrile bath and stirred at this temperature for 15 min under nitrogen. A solution of 3-amino-6-chloro-2-picoline (Oakwood Products, Inc., West Columbia, S.C., USA; 500 mg, 3.5 mmol) in 1,2-dimethoxyethane (16 mL) was added dropwise at −15° C. and the mixture was stirred at this temperature for 15 min. tert-Butyl nitrite (Aldrich Chemical Company, Inc., Milwaukee, Wis., USA 1.15 mL, 4.2 mmol) was added dropwise and the mixture was stirred at −15° C. for 15 min and then at 0° C. (ice/water bath) for 1 h. Hexane (20 mL) was added and the precipitate was filtered off and washed with hexane. This solid was added to acetic anhydride (5.00 g, 49 mmol) and the mixture was heated at 100° C. for 2 h. The acetic anhydride was evaporated under high vacuum and then 1 M aqueous sodium carbonate was added to pH 9. The mixture was stirred, and then extracted three times with dichloromethane. The solvent was evaporated and the residue purified using a silica gel column, eluting with 0-10% ethyl acetate) to give acetic acid 6-chloro-2-methyl-pyridin-3-yl ester (316 mg, 49%) as an oil.

1. additionwas added dropwise
2. stirringthe mixture was stirred at −15° C. for 15 min
3. filtrationthe precipitate was filtered off
4. washwashed with hexane
5. temperaturethe mixture was heated at 100° C. for 2 h
6. customThe acetic anhydride was evaporated under high vacuum
7. addition1 M aqueous sodium carbonate was added to pH 9
8. stirringThe mixture was stirred
9. extractionextracted three times with dichloromethane
10. customThe solvent was evaporated
11. customthe residue purified
12. washeluting with 0-10% ethyl acetate)

ORD record

ord-00ab6740f93f4a748f022de02112b08a

Source dataset

uspto-grants-2012_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08188098B2