tert-Butyl methyl ether → ethyl 3-(bromoacetyl)-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate

Participants

Reaction Steps

1.20 g (4.40 mmol) of ethyl 3-acetyl-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate were initially charged in in each case 30 ml of dioxane and methyl tert-butyl ether and 776 mg (4.85 mmol) of bromine were added dropwise at RT. The mixture was then stirred under reflux for 6 h. The reaction mixture was added to water, and the organic phase was separated off, dried over sodium sulphate and concentrated. The residue was recrystallized from methyl tert-butyl ether.

Provenance & Evidence