GB1428110A — Pharmaceutical antihypertensive and vasodilator compositions

USPTO Abstract

1428110 Benzothiepins; benzothiopyrans RECKITT & COLMAN PRODUCTS Ltd 17 May 1973 [30 May 1972] 25132/72 Heading C2C [Also in Division A5] Compounds of the general formula wherein n is 1, 2 or 3; p is 0, 1 or 2 and Y is -CH 2 -, -CHOH- or are prepared from dimethoxy thiophenols by the following reactions: (a) when Y is carbonyl and p is zero by reaction with an #-chloroalkanoic acid or a lactone in the presence of sodium ethoxide to form a dimethoxyphenylthioalkanoic acid which may be cyclized by heating in the presence of polyphosphoric acid; (b) when Y is methylene and p is zero by a Clemmenson reduction of a compound from reaction (a); (c) when Y is hydroxy methylene by reduction of a compound from (a) with LiAlH 4 . Compounds in which p is 1 may be obtained from those in which p is zero by oxidation using H 2 O 2 and acetic acid, N-bromo- or N-chloro-succinimide in methanol or 1-chlorobenzotriazole in methanol or CH 2 Cl 2 . preferably using an equimolecular amount of oxidizing agent. Compounds in which p is 2 may be obtained from those in which p = 0 by oxidation using excess H 2 O 2 in acetic acid at elevated (steam bath) temperatures.