Ethanol → ethyl 1-(4-chloro-2-methylbenzyl)-1H-indazole-3-carboxylate

Beteiligte Stoffe

Reaktionsschritte

To a suspension of 1-(4-chloro-2-methylbenzyl)-1H-indazole-3-carboxylic acid, prepared as described in J. Med. Chem. (1976) 19, 778-783, (120 g; 0.4 mol) in absolute ethanol (850 ml), stirred at room temperature, was cautiously added concentrated H2SO4 (15 ml). The mixture was then refluxed for 9 hours. The reaction was then completed by cooling the mixture to room temperature. The solid thus formed was filtered off under cold conditions (10° C.) and washed thoroughly on the filter with water. 126 g of ethyl 1-(4-chloro-2-methylbenzyl)-1H-indazole-3-carboxylate were thus obtained, and were used in the following reaction without further purification.

Herkunft & Nachweise