A process is described for the preparation of 3-isochromanone having the general formula (I): the process comprising reacting ο-tolylacetic acid with a suitable halogenating agent to form a compound of general formula (III): wherein R is halo, reacting the compound of general formula (III) with a suitable halogenating agent to form a compound of the general formula (II): wherein X is halo; and (a) treating a compound of the general formula (II): with an aqueous base to a pH of 7 to 14 followed by acidification; or (b) adding the compound of the general formula (II) to water with the simultaneous addition of base to maintain the pH between 5 and 8; or (c) treating the compound of the general formula (II)with water or aqueous acid followed by pH adjustment to a pH between 5 and 8. Typically both R and X are chloro. 3-Isochromanone is useful, inter alia, as an intermediate in the manufacture of agricultural products, especially fungicides of the strobilurin type.
Molecular modification of anticholinergics as probes for muscarinic receptors. 1. Amino esters of .alpha.-substituted phenylacetic acid and related analogs
作者:Matthias C. Lu、Walley E. Wung、Lisa B. Shih、Soledad Callejas、James E. Gearien、Emmanuel B. Thompson
DOI:10.1021/jm00385a008
日期:1987.2
Two series of compounds having the general structure of C6H5CRR'COOCH2CH2NEt2 were synthesized and examined for their antispasmodic activities. These compounds were selected as structural probes for exploring the nature of muscarinic cholinergic receptor binding sites that interact with atropine-like anticholinergics. These studies indicate a rather strict size limitation for the hydrophobic region
In the presence of a Cu(I) catalyst and a pyridine oxide, alkynyl oxiranes and oxetanes can be converted into functionalized five- or six-membered α,β-unsaturated lactones or dihydrofuranaldehydes. This new oxidative cyclization is proposed to proceed via an unusual allenyloxypyridinium intermediate.