Abstract: A process of preparing a tribromoneopentyl chloroalkyl phosphate of the formula (3): ##STR1## , wherein R is hydrogen atom, an alkyl or chloroalkyl group. The process includes three steps: In the first step, an alkylene oxide is reacted with phosphorus trichloride in a chemical equivalent or less amount to the alkylene oxide to obtain a tris(chloroalkyl) phosphite of the formula (1): ##STR2## , wherein R is the same as defined above. In the second step, the tris(chloroalkyl) phosphite is reacted with chlorine to obtain a bis(chloroalkyl) phosphorochloridate of the formula (2): ##STR3## , wherein R is the same as defined above. And in the third step, the bis(chloroalkyl) phosphorochloridate is reacted with tribromoneopentyl alcohol.

Abstract: A process of preparing tribromoneopentyl chloroalkyl phosphates comprising a first step of reacting phosphorus oxychloride with tribromoneopentyl alcohol and a second step of reacting the resultant formed in the first step with an alkylene oxide after a step of removing hydrochloric acid and unreacted phosphorus oxychloride present in the first reaction mixture to obtain a compound represented by the formula (1): ##STR1## , wherein R represents a hydrogen atom, or an alkyl or chloroalkyl group and n is from 0.95 to 1.15.