ethyl 4-amino-1H-imidazole-5-carboxylate → Ethyl 4-(2-thienyl)imidazo[1,5-a]pyrimidine-8carboxylate

Participants

Reaction Steps

A mixture of 1.55 g. (0.01 mols) of ethyl 4-amino-5-imidazolecarboxylate and 1.81 g. (0.01 mols) of 3-dimethylamino-1-(2-thienyl)-2-propen-1-one (prepared as described in Example 1, Part A) in 25 ml. of glacial acetic acid can be refluxed for 16 hours, then cooled and evaporated to dryness in vacuo. The residue can be dissolved in dichloromethane and passed through a short column of hydrous magnesium silicate. The effluent can be refluxed on a steam bath with a slow constant addition of n-hexane. At the first appearance of crystallization, heating should be curtailed and the solution allowed to cool. The precipitated material can be collected by filtration to produce ethyl 4-(2-thienyl)imidazo[1,5-a]pyrimidine-8carboxylate.

Provenance & Evidence