Reaction of 3,6-di(tert-butyl)-1,2-benzoquinone with terminal alkylacetylenes in the presence of phosphorus trichloride

Abstract

A reaction of 3,6 di(tert butyl) 1,2 benzoquinone with alkynes in the presence of phosphorus trichloride leads to a predominant formation of 4 alkyl and 4 haloalkyl 5,8 di(tert butyl) 2,6 dichloro 2H benzo[e][1,2]oxaphosphinine 2 oxide. An ipso substitution of the tert butyl group at ortho position to the oxygen atom of the benzophosphinine system with the formation of 4 alkyl 5 tert butyl 2,8 dichloro 2H benzo[e][1,2]oxaphosphinine 2 oxide was the minor route of the reaction with alkylacetylenes. Molecular structures of 4 butyl 5,8 di(tert butyl) 2,6 dichloro 2H benzo[e][1,2]oxaphosphinine 2 oxide and 5,8 di(tert butyl) 2,6 dichloro 4 hexyl 2H benzo[e][1,2]oxaphosphinine 2 oxide were studied by X ray analysis.