Acetic Acid → HCID 20228666, compound

Participants

Reaction Steps

The mixture of 5-(7-methylimidazo[1,2-a]pyridin-2-yl)-methyl-2-benzothiazolinone (1.9 g), 36% aqueous formaldehyde (1.07 g), 50% aqueous dimethylamine (1.16 g), acetic acid (772 mg) and methanol (10 ml) was stirred for 3 hours at 55°-60° C. The reaction mixture was concentrated under reduced pressure and the residue was dissolved in a mixture of lN hydrochloric acid (10 ml), water (10 ml) and ethyl acetate (30 ml). The separated aqueous layer was adjusted to pH 7 with 20% aqueous solution of potassium carbonate and the resultant aqueous mixture was extracted with ethyl acetate (50 ml×2). The extract was dried over magnesium sulfate and evaporated under reduced pressure to give a crystalline residue, which was re-crystallized from ethyl acetate to afford pale brown needles of 5-(3-dimethylaminomethyl-7-methylimidazo[1,2-a]pyridin-2-yl)-3-methyl-2-benzothiazolinone (1.56 g). mp. 167°-168° C.

Provenance & Evidence