Chloromethylation and Other Studies on Some Benzophenone Derivatives

2,4-Dihydroxybenzophenone did not give a pure product on chloromethylation but its dimethyl ether gave the 5-chloromethyl derivative. Similarly, 2,2'-dimethoxybenzopherione gave the 5,5'-di (chlorornethyl) derivative. The chlorornethyl derivatives have been converted into the acetoxymethyl derivatives and into the Mannich bases. They have been oxidised to the corresponding carboxylic acids and also converted into the corresponding formyl derivatives by heating with hexamine. 2,4'-Dimethoxy­5'-benzoylflavone, 7,2',4'-trirriethoxy-5'-benzoylflavone, bi(4'-methoxy-3'-fiavonyl) ketone and bi(7,4'- dirnethoxy-3'-flavonyl) ketone have been synthesised from these formyl derivatives through the inter­mediate chalkone derivatives. The Fries migration of 2,2'-diacetoxybenzophenone and the Friedel-­Crafts acetylation of 2,2'-dihydroxybenzophenone gave the 5,5'-diaoetyl derivative as the main product.