PURPOSE: To provide a novel derivative having an angiotensin I receptor- antagonizing action and useful as a hypertension-treating agent, a congestive heart failure-treating agent, etc.
CONSTITUTION: A compound of formula I [A is O when forming a double bond with the C of the pyrazole ring, or O-R4 (R4 is H, methyl, propionyl) when forming a single bond with the C of the pyrazole ring; R1 is hydroxycarbonyl, tetrazoyl; R2 is H, methyl, n-butyl, etc.; R3 is H, methyl, phenyl], or its medicinally usable salt. For example, 3-n-butyl-4-[2'-(hydroxycarbonyl)-biphenyl-4- yl]-methyl-pyrazol-5-one. The compound of formula I is obtained e.g. by reacting a compound of formula II (R5 is methoxycarbonyl, trityltetrazoyl; R6 is lower alkyl) with a hydrazine compound of the formula H2N-NH-R3 and subsequently hydrolyzing the produced compound of formula III with a 10% hydrochloric acid aqueous solution or a 75% acetic acid aqueous solution.
TOMIYAMA ITARU
YANAGISAWA TAKASHI
KAWAI TOMOYUKI
NISHIMURA HAJIME
