(1S,2R)-Cyclohexane-1,2-diamine, N1-BOC protected → {(1S,2R)-2-[6-carbamoyl-5-(1-methyl-1H-pyrazol-3-ylamino)-pyridazin-3-ylamino]-cyclohexyl}-carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

6-Chloro-4-(1-methyl-1H-pyrazol-3-ylamino)-pyridazine-3-carboxylic acid amide (60 mg, 0.237 mmol) and tert-butyl (1S,2R)-2-aminocyclohexylcarbamate (102 mg, 0.475 mmol) were dissolved in N-methylpyrrolidinone (1.5 mL). The reaction mixture was heated at 150° C. for 16 h, then additional tert-butyl (1S,2R)-2-aminocyclohexylcarbamate (100 mg, 0.47 mmol total) was added in three portions over 6 d. The reaction mixture was cooled, diluted with ethyl acetate and water, and extracted with ethyl acetate. The combined organic extracts were washed with water and brine, and then dried (sodium sulfate), filtered, and concentrated in vacuo. The residue obtained was purified by chromatography (silica, 0 to 7% methanol in dichloromethane) to give {(1S,2R)-2-[6-carbamoyl-5-(1-methyl-1H-pyrazol-3-ylamino)-pyridazin-3-ylamino]-cyclohexyl}-carbamic acid tert-butyl ester (18 mg, 17%) as a brown amorphous residue. 1H NMR (300 MHz, CHLOROFORM-d) δ ppm 10.68-10.80 (m, 1H) 7.89-8.06 (m, 1H) 7.34-7.37 (m, 1H) 7.25 (d, J=2.3 Hz, 1H) 5.93 (d, J=2.3 Hz, 1H) 5.56-5.64 (m, 1H) 5.02-5.14 (m, 1H) 3.91-4.01 (m, 1H) 3.86 (s, 3H) 1.55 (br. s., 8H) 1.40 (s, 9H); LCMS (EI/CI) m/z: 431 [M+H].

Provenance & Evidence