A novel and efficient protocol has been developed
for the synthesis of various spiro-5-cyanopyrimidines
via the three-component condensation of cyclic ketones,
nitrile derivatives, and thiourea or urea in ethanol at 60 C
using K2CO3 as catalyst under ultrasonic irradiation. In
comparison to conventional methods, high yields, easy
work-up, and short reaction times are advantages of this
sonocatalyzed procedure. The effects of the catalyst, solvent,
and temperature were examined.