Hydrochloric Acid → HCID 19913604, compound

Participants

Reaction Steps

A mixture of 7-propyl-3,4-dihydro-2H,5H-pyrimido[6,1-b][1,3]thiazine-6,8(7H)-dione (1 g), paraformaldehyde (0.22 g) and dimethylamine hydrochloride (0.51 g) in acetic acid (25 ml) was refluxed for 18 hours. The reaction solution was concentrated dryness, and the resulting residue was dissolved in water. Then, the solution was made basic with 1N aquaous sodium hydroxide, followed by extraction of the product with methylene chloride. After washing with water and drying, the organic layer was concentrated to dryness to obtain a syrup. The syrup was converted to the hydrochloride to form crystals, which were recrystallized from ethanol-ethyl acetate to give colorless prisms (0.46 g, 33%).

Provenance & Evidence