Benzyl Chloride → HCID 15703582, compound

Participants

Reaction Steps

Sodium (1.9 g) was dissolved in anhydrous ethanol (100 ml) to prepare a solution of sodium ethoxide. To this, were added 3-amino-4-ethoxycarbonylpyrazole (12.4 g) and benzyl chloride (10 g), and the resulted mixture was refluxed for 1 h. After filtration of the hot mixture, the filtrate was concentrated to quarter volume, and cooled to crystallize. The crude product was recrystallized from an ether-water mixture to give 3-amino-1-benzyl-4-ethoxycarbonylpyrazole (10.7 g, yield 44%). To a solution of 3-amino-1-benzyl-4-ethoxycarbonylpyrazole (0.2 g) in dried toluene (30 ml), were added propyl isocyanate (0.307 ml) and triethylamine (0.11 ml), and the mixture was refluxed in a sealed tube for 8 h. The reaction mixture was evaporated under reduced pressure followed by silica-gel column chromatography (toluene : ethyl acetate=20:1) to give the title compound (0.129 g, yield 48%). 1H-NMR (CDCl3) δ ppm: 0.92 (3H, t, J=7Hz, CH2CH2CH3 ), 1.32 (3H, t, J=7Hz, COOCH2CH3 ), 1.57 (2H, 6th, CH2CH2CH3), 4.28 (2H, q, J=7Hz, COOCH2CH3), 5.14 (2H, s, CH2 --Ph), 7.25 (5H, m, CH2 --Ph), 7.91 (2H, brs, NH), 8.00 (1H, s, C5-H)

Provenance & Evidence