2-Amino-6-methylpyridine → Ethyl 5-methylimidazo[1,2-a]pyridine-2-carboxylate

A solution of 6-methyl-2-pyridinamine (10 g, 93 mmol) [Aldrich, A75706] and ethyl bromopyruvate (15 mL, 110 mmol) in ethanol (93 mL) was heated at 90° C. for 4 h. The reaction mixture was concentrated, diluted with dichloromethane (250 mL), and washed with 10% aqueous potassium carbonate (200 mL). The aqueous layer was separated and extracted with additional dichloromethane (100 mL). The combined organic layers were washed with brine, dried with sodium sulfate, filtered, and concentrated to a crude solid. The solid was treated with diethyl ether (300 mL) and, after several minutes, the diethyl ether was decanted to give the desired product (19 g, quantitative) as a solid after drying under reduced pressure. This material was used without further purification. LCMS for C11H13N2O2 (M+H)+: m/z=205.1.

1. concentrationThe reaction mixture was concentrated
2. additiondiluted with dichloromethane (250 mL)
3. washwashed with 10% aqueous potassium carbonate (200 mL)
4. customThe aqueous layer was separated
5. extractionextracted with additional dichloromethane (100 mL)
6. washThe combined organic layers were washed with brine
7. dry with materialdried with sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated to a crude solid
10. additionThe solid was treated with diethyl ether (300 mL) and, after several minutes
11. customthe diethyl ether was decanted

ORD record

ord-872366e2bcfb4bd08e7cf8ae0076b42a

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09403847B2