Propionyl bromide → 4-(4-Bromo-2-fluorobenzyl)-3-n-butyl-1-[2-chloro-5-(propionylamino)phenyl]-1H-pyrazole-5-carbonitrile

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Reaction Steps

The acylation of 1-(5-amino-2-chlorophenyl)-4-(4-bromo-2-fluorobenzyl)-3-n-butyl-1H-pyrazole-5-carbonitrile (from Step G) with propionyl bromide in the presence of DMAP followed the procedure of Example 1, Step J. Flash chromatography of the crude product on silica gel (gradient elution with 5:1 to 3:1 hexane-EtOAc) afforded a 73% yield of the title compound as a tacky oil; homogeneous by TLC in 3:1 hexane-EtOAc; mass spectrum (FAB) m/e 517, 519 (M+1)+. 400 MHz 1H NMR (CDCl3) δ0.87 (t, J=7.3 Hz, 3H), 1.22 (t, J=7.6 Hz, 3H), 1.32 (m, 2H), 1.54 (m, 2H, partially obscured by H2O peak), 2.38 (q, J=7.6 Hz, 2H), 2.55 (t, J=7.8 Hz, 2H), 3.92 (s, 2H), 7.02 (dd, J≈8, 8.5 Hz, 1 H), 7.22-7.26 (m, 2H), 7.4-7.5 (m, 2H), 7.90 (d, J=2.2 Hz, 1H).

Provenance & Evidence