trans-Cyclohexane-1,2-diamine, cas is 1121-22-8, it is a common heterocyclic compound, the chiral-catalyst compound, its synthesis route is as follows.,1121-22-8
Into a solution containing 1,6-diisocyanatohexane (4.04 grams, 24.0 mmol; obtained from Sigma-Aldrich Fine Chemicals, Milwaukee, Wis.) and anhydrous tetrahydrofuran (100 mL, Sigma-Aldrich Fine Chemicals, Milwaukee, Wis.) stirring at room temperature was added 2-ethylhexanol (3.13 grams, 24.0 mmol, obtained from Sigma-Aldrich Fine Chemicals) and dibutyltin dilaurate (0.38 grams, 0.6 mmol, obtained from Sigma-Aldrich Fine Chemicals) as the catalyst. The mixture was stirred and heated to an internal temperature of about 70 C. The progress of the reaction was monitored by 1H-NMR spectroscopy for the consumption of 2-ethylhexanol starting material, indicated by the disappearance of the -CH2OH multiplet, which appears at 3.5 ppm as a shoulder peak on the downfield end of the intermediate isocyanate product whose signal is located at 3.35-3.40 ppm. The mixture was cooled to about 5 C. internal temperature; thereafter, to this mixture was added dropwise a solution of trans-1,2-diaminocyclohexane (1.37 grams, 12 mmol; obtained as a racemic mixture of (1R,2R) and (1S,2S) stereoisomers from Sigma-Aldrich Fine Chemicals) dissolved in anhydrous tetrahydrofuran (10 mL). The mixture was stirred for about 30 minutes while warming up to room temperature, and thickened to form a gelatinous slurry. FTIR spectroscopic analysis of a reaction sample showed very little unreacted isocyanate (peak at 2180 cm-1, sample prepared as a KBr pellet). Residual isocyanate was quenched by addition of 5 mL of methanol. A crystalline product was isolated from the slurry by first adding methylene chloride (40 mL) followed with stirring for approximately 20 minutes to ensure full precipitation out of the gel slurry. The solid was filtered by suction on a paper filter, rinsed with methylene chloride (about 10 mL), and then dried in air to give 7.36 grams of off-white solid (86% yield). The product was believed to be of the formulae 1H-NMR spectroscopic analysis of the solid was performed in DMSO-d6 (300 MHz) at high temperature (60 C.) and indicated the above structure, with the following assigned peaks: 0.90 ppm (multiplet, 6 H integration, -OCH2CH(CH2CH3)CH2CH2CH2CH3); 1.0-1.95 ppm (broad multiplets, 20 H integration, 8 methylene protons from 2-ethylhexanol portion, 8 methylene protons from the 1,6-diisocyanatohexane portion, and 4 methylene protons from the cyclohexane ring portion); 2.95 ppm (narrow multiplet, 4 H integration, -NH(CO)NHCH2(CH2)4CH2NH(CO)O); 3.20 ppm (broad singlet, 1 H integration, tertiary methine proton adjacent to urea group on cyclohexane ring); 3.90 ppm (doublet, 2 H integration, OCH2CH(CH2CH3)CH2CH2CH2CH3); 5.65 ppm and 5.75 ppm (each a broad singlet, 1 H integration, urea NH protons); 6.75 ppm (broad singlet, 1 H integration, urethane NH proton). Elemental analysis calculated for C: 64.19%, H: 10.49%, N: 11.82%; found for C: 61.70%, H: 9.86%, N: 14.91%.
1121-22-8 is used more and more widely, we look forward to future research findings about trans-Cyclohexane-1,2-diamine
Reference£º
Patent; Xerox Corporation; US2006/122415; (2006); A1;,
Chiral Catalysts
Chiral catalysts – SlideShare