N,N'-bis(chloroacetyl)-trans-1,2-diaminocyclohexane was prepared according to the procedure outlined by Saburi, M. and Yoshikawa, S., "Stereochemical studies of N-methyl-(S)-alaninatocobalt(III) complexes with chiral tetraamines. II. Cobalt(III)-N-methyl(S)- and (R)-alaninate-N,N'-bis(β-aminoethyl)-1(R), 2(R)-diaminocyclohexane systems," Bull. Chem. Soc. Jpn., 1974, 47, 1184-1189. Anhydrous sodium carbonate (250 g., 2.36 mol.) was added to a solution of 33.4 g. (125 mmol.) of N,N'-bis(chloroacetyl)-trans-1,2-diaminocyclohexane and 15 ml. (125 mmol.) of trans-1,2diaminocyclohexane in 3750 ml. of acetonitrile. The temperature was raised to 82° C., and the reaction mixture was violently agitated for 20 hours. At the end of the reaction, sodium carbonate was eliminated by filtration and the solvent was evaporated under vacuum. The solid residue was recrystallized from ethanol. Up to five successive batches of the desired compound were obtained after the progressive concentration of the ethanolic solution under vacuum. The yield was 9.6 g. of compound (A) as a white powder.
