Patent GB-567807-A (GB)
Title: Triphenylethylene derivatives
IPC: C07C43/14
Filed: 1943-07-21
Abstract: Triphenylethylene derivatives of the general formula <FORM:0567807/IV/1> wherein X represents chlorine or bromine, and of R and R1 one represents ethoxy and the other hydrogen, are made by the interaction of the correspondingly substituted triphenylethylene in which X represents H or the correspondingly substituted triphenylethanol of the formula <FORM:0567807/IV/2> dissolved in an inert organic solvent with an approximately equi-molecular proportion of chlorine or bromine.  The above substituted triphenylethanols are obtainable by a Grignard reaction between di-p-ethoxy-desoxybenzoin and a phenyl magnesium halide or between p1-ethoxydesoxy benzoin and a p-phenetyl magnesium halide, followed by hydrolysis of the organomagnesium compound.  Alternatively, the substituted triphenyl ethanol, wherein R represents H and R1 represents ethoxy, is obtainable by a Grignard reaction between an ester of phenylacetic acid and 2 molecular proportions of a p-phenetyl magnesium halide, followed by hydrolysis of the organomagnesium compound.  The substituted triphenylethylenes, used as starting materials, are obtainable by dehydrating the corresponding carbinols, e.g. by treatment with sulphuric acid, hydrochloric acid, acetyl chloride or phosphorous tribromide.  Alternatively, the dehydration step may be merged with the decomposition of the Grignard compound, e.g. by using 20 per cent aqueous hydrochloric or sulphuric acid. Examples relate to the preparation of (1) a  : a -di-p-phenetyl-b -phenyl-b -bromoethylene by mixing a  : a -di-p-phenetyl-b -phenyl ethanol in glacial acetic acid with bromine in glacial acetic acid at 20 DEG -30 DEG  C. and allowing the mixture to stand for 24 hours; (2) the same product similarly from a  : a  - di - p - phenetyl - b  - phenylethylene; (3) a  : b -di-p-phenetyl-a -phenyl-b -bromoethylene, similarly from a  : b -di-p-phenyl-a -phenyl-ethanol; (4) a  : a  -di - p - phenetylb  - phenylethanol, by the action of a Grignard reagent, made from magnesium and p-bromophenetole in ethereal solution, upon p1-ethoxydesoxybenzoin, followed by hydrolysis with a saturated solution of ammonium chloride and extraction of the product with benzene; (5) a  : a  - di - p - phenetyl - b  - phenylethanol, by the action of a Grignard reagent, made from bromophenetole and magnesium in ethereal solution, upon ethyl phenylacetate followed by hydrolysis and extraction as in (4); (6) a  : a -di-p-phenetyl-b -phenylethylene by dehydration by heating at 100 DEG  C. for 5 minutes with 15 per cent aqueous hydrochloric acid of a product obtained by the action of a Grignard reagent, made from benzyl chloride and magnesium in ethereal solution, upon p : p1-diethoxybenzophenone, followed by hydrolysis and extraction as in (4); (7) a  : b -di-p-ethoxyphenyl-a -phenylethanol, by the action of a Grignard reagent, made from bromobenzene and magnesium in ethereal solution, upon p : p1-diethoxy-desoxybenzoin, followed by hydrolysis and extraction with ether.  p : p1-Diethoxydesoxybenzoin is made by reaction of p-ethoxyphenyl acetyl chloride (prepared by the action of thionyl chloride on p-ethoxyphenylacetic acid) with phenetole, in carbon disulphide solution in presence of anhydrous aluminium chloride. Specification 518,149 is referred to.