Thionyl Chloride → Methyl 3-aminopyridine-4-carboxylate

A suspension of 3-aminoisonicotinic acid (13.81 g, 100 mmol, prepared using the procedure described in Crum J. D.; Fuchsman, C. H. J. Heterocyclic Chem., 1966, 3, 252) in methanol (250 mL) was treated with thionyl chloride (14.7 mL, 200 mmol) and heated to reflux for 3 days. The yellow solution was concentrated to dryness to provide a yellow solid. This solid was suspended in 200 mL of ethyl ether and treated with 400 mL of saturated, aqueous NaHCO3 and the biphasic solution was stirred until all of the solids were dissolved. The layers were separated and the aqueous phase was extracted with 2 additional portions of ethyl ether. The combined organic phases were washed with water and brine, dried (Na2SO4), filtered, and concentrated to provide the title compound as a light yellow solid. MS (DCI/NH3) m/z 153 (M+H)+.

1. customprepared
2. temperatureheated
3. temperatureto reflux for 3 days
4. concentrationThe yellow solution was concentrated to dryness
5. customto provide a yellow solid
6. dissolutionwere dissolved
7. customThe layers were separated
8. extractionthe aqueous phase was extracted with 2 additional portions of ethyl ether
9. washThe combined organic phases were washed with water and brine
10. dry with materialdried (Na2SO4)
11. filtrationfiltered
12. concentrationconcentrated

ORD record

ord-81eb1197194b49d7ae3ccd72da2f9e0d

Source dataset

uspto-grants-2001_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06277871B1