Dimethylformamide → 1-[4,5,6-Trichloro-1-(2-methoxy-ethoxymethyl)-1H-benzoimidazol-2-yl]-1H-pyrazole-4-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of 2,4,5,6-tetrachloro-1-(2-methoxy-ethoxymethyl)-1H-benzoimidazole (0.275 g, 0.80 mmol), Cs2CO3 (0.524 g, 1.61 mmol), 1H-pyrazole-4-carboxylic acid ethyl ester (0.124 g, 0.89 mmol), and DMF (4 mL) was heated to 80° C. for 2 h. The mixture was cooled to 23° C. EtOAc was added and the mixture was washed with brine. The organic layer was dried (MgSO4), filtered, and concentrated under reduced pressure. The residue was purified (FCC) to yield the titled compound as a mixture of regioisomers (0.166 g, 46%). MS (ESI/CI): mass calcd. for C17H17Cl3N4O4, 446.0; m/z found, 447.0 [M+H]+. 1H NMR (400 MHz, DMSO-d6): 9.01-8.97 (m, 2H), 8.40 (t, J=2.3 Hz, 1H), 8.37 (s, 1H), 8.21 (s, 1H), 8.13 (s, 1H), 6.09 (s, 2H), 6.01 (s, 2H), 4.30 (qd, J=7.1 Hz, 2.9, 8H), 3.58-3.51 (m, 2H), 3.44 (d, J=4.9 Hz, 2H), 3.11 (s, 3H), 3.08 (s, 3H), 1.32 (tt, J=7.1 Hz, 1.7 Hz, 6H).

Provenance & Evidence