Tris(trimethylsilyl)phosphite (TMSP) was reacted with 1- and 2-Chloroethylchloroformate followed by hydrolysis. The purpose of the work was to determine the reactivity of TMSP with compounds having two different reactive functional groups: acyl and halide. Arbuzov and Perkow types of the reactions were expected; however, only the identification of the product(s) could explain the final outcomes of the reactions. Preliminary results will be discussed.