反应详情

温度

90 °C

A mixture of 1.0 g (0.006 mol) 3,4-dihydro-2(1H)-quinazolinethione (compound II), 0.57 g (0.006 mol) chloroacetic acid, and 0.54 g (0.0065 mol) sodium bicarbonate is mixed in 31.25 ml water, and heated overnight at 90° C. Then, 12.5 ml of dimethylformamide is added, and the reaction mixture is refluxed for 61/2 hours. After cooling, 5H-thiazolo[2,3-b]quinazolin-3(2H)-one, as the precipitated solid, is filtered off and recrystallized from anhydrous ethanol. Replacement of 3,4-dihydro-2(1H)-quinazolinethione by a derivative thereof in which a nuclear hydrogen of the benzene ring has been substituted with lower alkyl, alkoxy, halogen, trifluoromethyl, NO2 or NH2, results in the corresponding derivative of 5H-thiazolo[2,3-b]quinazolin-3(2H)-one.

1. temperaturethe reaction mixture is refluxed for 61/2 hours
2. temperatureAfter cooling
3. filtration5H-thiazolo[2,3-b]quinazolin-3(2H)-one, as the precipitated solid, is filtered off
4. customrecrystallized from anhydrous ethanol