Hydrochloric Acid → HCID 19973434, compound

Participants

Reaction Steps

In a nitrogen atmosphere, 78.56 g of magnesium was added to 2 l of tetrahydrofuran and 0.3 g of iodine and 18 ml of bromoethane were added to the obtained mixture to prepare a Grignard reagent. A solution of 170.5 g of 6-bromo-2-methylimidazo[1,2-a]pyridine and 162 ml of bromoethane in 500 ml of tetrahydrofuran was slowly dropped into the above reaction mixture. After the completion of the dropping, the obtained mixture was heated under reflux for 30 minutes and then cooled with ice. Formaldehyde gas generated by heating a container containing 242 g of paraformaldehyde to 200° C. was introduced into the reaction mixture by the use of a nitrogen stream. After 30 minutes, dilute hydrochloric acid was added to the resulting mixture and the obtained mixture was filtered to remove insolubles. The filtrate was alkalinized with concentrated aqueous ammonia and extracted with chloroform. The organic phase was dried over anhydrous magnesium sulfate and distilled to remove the solvent. The residue was purified by silica gel column chromatography [solvent: dichloromethane/methanol (30:1 to 10:1)] to give 120 g of the title compound as a pale-yellow solid (yield: 91.9%).

Provenance & Evidence