Sodium hydride → Ethyl 3-amino-1-[(4-methoxyphenyl)methyl]-1H-pyrazole-4-carboxylate

Participants

Reaction Steps

To a solution of 3-amino4-carbethoxypyrazole (15 g, 96.7 mmol) in acetonitrile (750 mL) was add NaH (60% oil dispersion, 4 g, 100 mmol) at rt. After 15 min., 4-methoxybenzyl chloride (15.7 g, 100 mmol) was added with stirring. The reaction was allowed to run for 24 h. The reaction mixture was then diluted with EtOAc and washed with H2O, brine and dried (Na2SO4). Removal of the solvent gave the crude product which was further purified by flash column (silica gel, EtOAc/hexane, 1:1) to give ethyl 5-amino-2-p-methoxybenzyl-4-pyrazolecarboxylate (4.2 g, LC: 3.10′ MH+: 276) along with Ethyl 5-amino-1-p-methoxybenzyl-4-pyrazolecarboxylate (4.5 g) (LC: 3.07′ [Gradient 1] MH+: 276) and mixture of the two (10.2 g).

Provenance & Evidence