Optical resolution of the racemic isomer

All three isomers of frans-diammine(trien)cobalt(III) chloride (or perchlorate) are very soluble in water but sparingly soluble in ethanol. Although the solid complex salts are stable for over a year when stored in a refrigerator (5°), they 

Nokami, H. Kanno, and S. Utsuno, Chem. Lett., 1981, 371. 

11-TETRAAZAC YCLOTETRADEC ANE-5,7-DIONE (dioxocyclam) COPPER(II) AND AQUEOUS COPPER(III) 

Snbmitted by LUIGI FABBRIZZI, ANTONIO POGGI, and BARBARA SEGHI Checked by D. B. MORSE and D. H. BUSCHt 

Diethyl malonate, 15 g (0.093 mole), purified by distillation under reduced pressure, and 15 g (0.093 mole) of H2N(CH2)2NH(CH2)3NH(CH2)2NH2, conveniently prepared according to the procedure described in reference 2, are dissolved in 1900 mL of absolute ethanol, contained in a 3-L round-bottomed flask, to give a 5 x 10-2 M solution, which is refluxed for five days. The yellow solution is evaporated to about 100 mL on a rotary evaporator and is allowed to stand at room temperature in a corked bottle. In two to three days or less, white crystals form, which are removed by filtration, washed with small portions of cold ethanol and diethyl ether, and dried under vacuum. The yield is 5.5 g (24%). Anal. Calcd. for C10H2oN402 C, 52.61 H, 8.83 N, 24.55. Found C, 52.30 H, 8.87 N, 24.77. 

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