Formic Acid → 5-(Acetylamino)methylimidazo[5,1-b]thiazole

Participants

Reaction Steps

To a solution of 100 mg (0.59 mmol) of the above-obtained 5-(N-methylamino)methylimidazo[5,1-b]thiazole in 3 ml of methylene chloride was added a mixture which had been prepared in advance by reacting 1 ml of formic acid with 0.2 ml of acetic anhydride at 50° C. for 10 minutes. The mixture was stirred at room temperature for one hour, and then refluxed for 3 hours. To this was added a mixture which had been prepared in advance by reacting 5 ml of formic acid with 2 ml of acetic anhydride at 50° C. for 10 minutes, and the mixture was refluxed for an additional 2 hours. To the reaction solution cooled to room temperature was added 3 ml of toluene, and the mixture was concentrated to dryness under reduced pressure. To the residue were added methylene chloride and a 50% aqueous solution of potassium carbonate, and the mixture was stirred for 10 minutes. The organic layer was separated, and the aqueous layer was extracted three times with methylene chloride. The combined organic layers were dried over anhydrous potassium carbonate, concentrated under reduced pressure, and purified by flash column chromatography using silica gel, eluting with a 9:1 mixture of ethyl acetate and methanol to give 89 mg (yield 77%) of the title compound as colorless crystals.

Provenance & Evidence