1-cyclohexyl-iMidazole synthesis

Yield:67768-61-0 50%

Reaction Conditions:

with phosphoric acid;ammonium chloride in water; for 12 h;Reflux;

Steps:

3.1 1-Cyclohexyl-1H-imidazole

This compound was prepared by amending a previously published method [22]. Ammonium chloride (10.7g, 0.200mol), glyoxal (40%, 15.3mL, 0.134mol), formaldehyde (30%, 16.0mL, 0.134mol), and deionized water (250mL) were combined in a 1L round bottom flask. In a separate flask, a solution of cyclohexylamine (11.5mL, 0.100mol) in deionized water (100mL) was acidified with phosphoric acid (85%, 15mL). The acidified amine was added to the ammonium chloride solution. After heating the resulting colorless solution at reflux for 12h, the clear orange solution was cooled to room temperature and subsequently poured into a 1L beaker that was half-filled with ice. The resulting mixture was made basic with sodium hydroxide (40%) until the pH was in the range of 10-12. The product was then extracted into ethyl acetate and the organic layer was washed with water and dried over sodium sulfate. Following removal of the solvent under reduced pressure, the desired product was purified via vacuum distillation (105°C) to give 7.5g of the title compound as a colorless oil. Yield=50%. ¹H NMR (400MHz, CDCl₃, 25°C) δ/ppm: 7.53 (s, 1H), 7.04 (s, 1H), 6.95 (s, 1H), 3.90 (tt, J=11.8, 3.8Hz, 1H), 2.12-2.09 (m, 2H), 1.92-1.87 (m, 2H), 1.79-1.70 (m, 1H), 1.67-1.57 (m, 2H), 1.45-1.35 (m, 2H), 1.29-1.18 (m, 1H). ¹³C NMR (101 MHZ, CDCl₃, 25°C) δ/ppm: 135.43, 129.03, 117.10, 56.90, 34.54, 25.54, 25.34. HR-EI-MS [M]⁺ m/z: calculated for C₉H₁₄N₂ 150.1157; found, 150.1162.

References:

Andrade, Gabriel A.;DiMeglio, John L.;Guardino, Eric T.;Yap, Glenn P.A.;Rosenthal, Joel [Polyhedron,2017,vol. 135,p. 134 - 143]