Acetic Acid → 4-Oxo-4H-pyrimido[2,1-a]isoquinoline-3-carboxylic Acid

Participants

Reaction Steps

A solution of ethyl 4-imino-4H-pyrimido[2,1-a]isoquinoline-3-carboxylate (1.0 g.) in acetic acid (20 ml.) and 37% hydrochloric acid (20 ml.) was refluxed for 35 minutes. The solution was cooled and diluted with H2O to precipitate the crude acid (760 mg.), m.p. 219°-231° (prior softening). Recrystallized material (2-methoxyethanol) and a m.p. of 249°-252° and mixed melting point of 252°-255° with product from Example 2.

Provenance & Evidence