Chloroacetaldehyde → Methyl imidazo(1,2-a)pyridine-7-carboxylate

関与物質

反応手順

To a solution of 2-amino-isonicotinic acid methyl ester (1 eq.) and chloroacetaldehyde (45% w/w in water) (4.5 eq.) in ethanol was added NaHCO3 (1.7 eq.). The reaction mixture was refluxed for 15 h and the solvents removed under reduced pressure. The residue was partitioned between water and EtOAc, the organic layer was washed with a saturated aqueous solution of Na2CO3 and brine, dried over MgSO4, filtered and concentrated under reduced pressure. The crude was purified by chromatography on silica gel (elution with DCM/MeOH: 100/0 to 98/2) to afford imidazo[1,2-a]pyridine-7-carboxylic acid methyl ester.

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