Buquineran

Originator

Buquineran,Pfizer Central Research

Manufacturing Process

4-Chloro-6,7-dimethoxyquinazoline (45.0 g), 4-(3-n-butylureido)piperidine monhydrochloride (80.0 g) and triethylamine (140 ml) were refluxed in ethanol (450 ml) for 1.25 h. The mixture was then concentrated in vacuo and the resultant solid was stirred in water which was then basified to pH 11 with 5 N NaOH solution. The suspension was shaken with chloroform and the organic layer was separated, dried (Na2CO3) and evaporated to dryness in vacuo to give a yellow oily solid. Trituration with ether followed by recrystallization from ethanol gave the product (37.0 g) with small traces of impurities, wich were removed by running a chloroform solution of it down a glass column packed with "Florisil" and eluting with 10% isopropanol in chloroform.
After evaporation, appropriate fractions were bulked to give a pure 4-(4-[3-nbutylureido] piperidino)-6,7-dimethoxyquinazoline, melting point 204-205°C (21.0 g; recrystallized from ethanol).

Therapeutic Function

Coronary vasodilator