Hydrochloric Acid → [1-[4-(aminosulfonyl)phenyl]-5-(4-chlorophenyl)-1H-pyrazol-3-yl]acetic acid

Participants

Reaction Steps

To a solution of 4-[5-(4-chlorophenyl)-3-(cyanomethyl)-1H-pyrazol-1-yl]benzenesulfonamide from step 2 (0.340 g, 3.594 mmol) in ethanol (250 mL) at −10° C., HCl gas was added via a fritted gas inlet tube over 6 hours. The reaction mixture was concentrated in vacuo yielding an oil. The oil was dissolved in 50 mL of ethanol and 15 mL of water, treated with LiOH until the pH was 12, and stirred at room temperature overnight. The reaction was concentrated in vacuo, diluted with water, acidified with dil HCl, and extracted with ethyl acetate. The ethyl acetate phase was dried over anhydrous MgSO4, filtered and concentrated yielding [[1-[4-(aminosulfonyl)phenyl]-5-(4-chlorophenyl)-1H-pyrazol-3-yl]acetic acid as a brown solid (1.072 g, 76%): mp 120-122° C. High resolution mass spectrum Calc'd. for C17H15ClN3O4S (M+H): 392.0472. Found: 392.0467. 1 h NMR (CDCl3 and CD3CO2D) 7.84 (d, J=8.66 Hz 2 H), 7.37 (d, J=8.66 Hz, 2 H), 7.31 (d, J=8.66 Hz, 2 H), 7.15 (d, J=8.66 Hz, 2 H), 6.54 (s, 1H), 3.84 (s, 2H).

Provenance & Evidence