(1S,2S)-1,2-Diaminocyclohexane

Abstract

1,2-Diaminocyclohexane [694-83-7] trans-1,2-Diaminocyclohexane [1121-22-8] (1R,2R)-1,2-Diaminocyclohexane [20439-47-8] (1S,2S)-1,2-Diaminocyclohexane [21436-03-3] C6H14N2 (MW 114.2) InChI = 1S/C6H14N2/c7-5-3-1-2-4-6(5)8/h5-6H,1-4,7-8H2/t5-,6-/m0/s1 InChIKey = SSJXIUAHEKJCMH-WDSKDSINSA-N (chiral compound, chiral auxiliary, chiral ligand, chiral catalyst) Physical Data: mp 42–45 °C; bp 104–114 °C 40 mm Hg; [α]D20 + 25 (c 5, 1 N HCl). Solubility: soluble in aqueous acidic solution, alcohols, and most organic solvents. Form Supplied in: colorless liquid; both enantiomers are commercially available. Preparative Methods: cheap and readily available racemic trans-1,2-diaminocyclohexane can be resolved with d-(−)-tartaric acid, giving (1S,2S)-diaminocyclohexane with > 9 + 8% enantio-meric excess. Detailed procedures for the resolution have been published.2, 3 Determination of enantiomeric excess is made by HPLC analysis of the N,N′-bis(m-toluyl) derivative on a Pirkle l-Leucine-DNB column. Direct separation of enantiomers by preparative HPLC on a chiral column has also been described.4 The (S,S)-enantiomer has been obtained with optical purity higher than 99% by resolution of racemic trans-1,2-diaminocyclohexane using fractional crystallization of diastereomeric salts of dehydroabietic acid.58 Candida antarctica lipase (CAL) catalyzes the aminolysis of racemic trans-1,2-diaminocyclohexane using dimethyl malonate as acyl donor, providing an enantiopure (R,R)-bisimidoester, while enantiomerically enriched unreacted (S,S)-diamine can be isolated as its air-stable ammonium salt after treatment with anhydrous HCl.56 Purity: bulb-to-bulb vacuum distillation. Handling, Storage, and Precautions: air- and CO2-sensitive; bottles should be stored under an inert gas atmosphere, preferably away from direct light. 1,2-Diaminocyclohexane is harmful by inhalation and contact with skin. May be fatal if swallowed. Incompatible with strong acids and strong oxidizing reagents.