Novel benzopyranylpyrrolinone derivatives.

摘要

Compounds of the formula <CHEM> wherein: R1 is cyano or nitro; R2 and R3 are independently hydrogen or lower alkyl; and R4 is alkyl; alkenyl; optionally substituted phenyl or phenyl lower alkyl; -(CH2)mOR2 or -(CH2)mN(R2)2; wherein m is an integer of 1-5 and R2 is as defined above; or a pharmaceutically acceptable ester or acid addition salt thereof; are smooth muscle relaxants, particularly useful in the treatment of hypertension.