Analogs of 3-quinuclidinyl benzilate

Abstract

A number of analogs of 3-quinuclidinyl benzilate (QNB) [potential myocardial imaging agents] were synthesized and their affinities to muscarinic receptor from rat or dog ventricular muscle were measured. The muscarinic receptor can to a different degree accommodate either a halogen in the o, m or p position of 1 phenyl ring or the replacement of 1 phenyl ring with an alkyl group. In vitro competition studies show that the affinities lie within a 270-fold range, from the highest affinity compound, 3-quinuclidinyl .alpha.-hydroxy-.alpha.-cyclopentylphenylacetate, to the lowest affinity compound, 3-quinuclidinyl .alpha.-hydroxy-.alpha.-2-propargylphenylacetate.