1,1'-Carbonyldiimidazole → 4-(6-Oxo-1,4,5,6-tetrahydropyridazin-3-yl)benzyl 4-(3-chlorophenyl)-1,4-dihydro-2,6-dimethyl-5-nitropyridine-3-carboxylate

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Reaction Steps

10 mmol of 4-(3-chlorophenyl)-1,4-dihydro-2,6-dimethyl-5-nitropyridine-3-carboxylic acid are suspended in 40 ml of absolute tetrahydrofuran and treated with 12.5 mmol of carbonyldiimidazole. The suspension is then stirred for 30 minutes at room temperature and for 30 minutes at reflux temperature. A solution of 11 mmol of 4-(6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)benzyl alcohol and 10 mg of sodium methylate in 10 ml of tetrahydrofuran is then added, and the mixture is heated to reflux for 3.5 hours. It is then evaporated, and the residue is taken up in methylene chloride, washed successively with 1N hydrochloric acid, 1N sodium hydroxide solution and water, dried with magnesium sulphate and evaporated. The residue crystallizes from a little i-propanol.

Provenance & Evidence