T 2237 (OTTO) Trimethyl phosphite, 99% Cas no 121-45-9 - used in chemical synthesis as a reactant in the reaction Michaelis-Arbuzov. T 2237 (OTTO) Trimethyl phosphite, 99% Cas no 121-45-9 used as a ligand in organometallic chemistry and as a reagent in organic synthesis.