Synthesis and characterization of 6-substituted dibenzo [d,f] [1,3,2] dioxa phosphepin 6-oxides

Several 6-trichloromethyl dibenzo[d,f] [1,3,2] dioxaphosphepin 6-oxide (3a), 2-chloroethoxy dibenzo[d,f] [1,3,2] dioxaphosphepin 6-oxide (3b) and alkylcarbamato dibenzo [d,f] [1,3,2] dioxaphosphepin 6-oxides (6a-c) have been synthesized from reactions of equimolar quantities of 2,2'-dihydroxybiphenyl (1) with trichloromethylphosphonic dichloride (2a), O-2-chloroethyl phosphoryldichloride (2b) and dichlorophosphinyl carbamates (5a-c) at 45-50 degreesC for (3a & 3b) and 40-45 degreesC for (6a-c) in dry toluene in the presence of triethylamine. Elemental, IR and NMR (H-1 & P-31) data have been discussed and supported all structures.