Acetic Acid → N-Cyclohexyl-2-phenyl-2H-indazol-3-amine

Participants

Reaction Steps

To a solution of 2-phenyl-2H-indazol-3-amine (800 mg, 4 mmol; Shirtcliff, Laura D.; Rivers, Jazmin; Haley, Michael M, Journal of Organic Chemistry (2006), 71(17), 6619-6622) in CH2Cl2 (43 ml) was added cyclohexanone (1.97 ml, 19 mmol; CAS Reg. No. 108-94-1), acetic acid (0.22 ml, 4 mmol) and sodium triacetoxyborhydride (2.43 g, 11 mmol) at ambient temperature under an argon atmosphere. The reaction mixture was heated under reflux conditions for 12 h, poured onto ice water/aqueous NaHCO3 solution 1/1 and extracted two times with CH2Cl2. The combined extracts were washed with ice water/brine 1/1 and dried over Na2SO4. After filtration the solvent was removed under reduced pressure, the resulting brown oil was dissolved in MeOH (20 ml) and heated under reflux conditions for 30 min. Removal of the solvent under reduced pressure left a brown oil which was purified by column chromatography (silica gel, iPrOAc/heptane) to give the title compound (206 mg, 0.7 mmol; 18%) as yellow oil. MS: m/e=292.4 [M+H+].

Provenance & Evidence