Hydrochloric Acid → isopropyl 1-methyl-5-(2-phenyl-[1,2,4]triazolo[1,5-a]pyridin-7-ylcarbamoyl)-1H-pyrazole-4-carboxylate

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Reaction Conditions

Reaction Steps

A white suspension of 1-methyl-5-(2-phenyl-[1,2,4]triazolo[1,5-a]pyridin-7-ylcarbamoyl)-1H-pyrazole-4-carboxylic acid (90 mg, 248 mol.) and 2-propanol (23 l, 298 mol) in N,N-dimethylformamide (2 ml) is cooled to 0° C. A solution of 4-dimethylaminopyridine (15.2 mg, 124 mol, 0.5 eq.) and PYBROP (127 mg, 273 mol, 1.1 eq.) in N,N-dimethylformamide (2 ml) is dropwise added at 0° C. followed after 5 min by triethylamine (105 l, 745 mol). The white suspension is allowed to warm to room temperature giving a colorless clear solution and stirred for 4.5 days. The colorless solution is poured on water, neutralized to pH 7-8 with aqueous 1N hydrochloric acid and extracted with dichloromethane (3×70 ml). The combined aqueous layer is washed with water (3×50 ml), dried with magnesium sulfate and the solvent is removed in vacuo. Purification of the residue (77 mg) by chromatography on a 10 g silica cartridge (eluent heptane/ethyl acetate 30-60% 25′) affords isopropyl 1-methyl-5-(2-phenyl-[1,2,4]triazolo[1,5-a]pyridin-7-ylcarbamoyl)-1H-pyrazole-4-carboxylate (10 mg, 9.96%) as a white solid. MS: m/z=405.3 (M+H+).

Provenance & Evidence