Abstract
The mechanism for the formation of γ-methyl-N-carboxy-L-glutamate anhydride (MLG·NCA) by use of trichloromethyl chloroformate (TCF) was studied in a solvent system of chlorobenzene-dioxane (15 : 1 volume ratio). The reaction was followed by measuring the reaction temperature, the amount of remaining MLG and formed NCA at time intervals. The results revealed that the reaction was composed of two stages ; the frist stage was the reactions[1][3] and the subsequent stage was the reactions [4] and [5].
RC-NH2H-COOH+Cl-C-O-O-CCl3→ RC-NH-C-O-OCCl3H-COOH+HCl→R C-NH-CO-O-H-CO-O-+COCl2+2HCl [1]
RC-NH2-H-COOH+COCl2→R-NHCOCl-CH-COOH+HCl→RC-NH-CO-O-H-CO-O+2HCl [2]
4RC-NH2-H-COOH+ 4 HCl→4 R C-NH2·HCl-H-COOH [3]
RC-NH2·HCl-H-COOH+Cl-C-O-O-CCl3→RC-NH-C-O-OCCl3H-COOH+2HCl→RC-NH-CO-OH-OCO-O+COCl2+3HCl [4]
RC-N2·HClH-COOH+COCl2→RC-NHCOOlH-CO0H+2HCl→RC-NH-CO-OH-OCO-O+3HCI [5]
