Benzaldehyde → HCID 58478762, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 2,2,6,6-tetramethyl-piperidine (7.5 ml, 44 mmol) in a 250 ml round bottomed flask equipped with a magnetic stirrer, is put under argon atmosphere and 30 ml of dry THF is added. The reaction mixture is cooled to −50° C. by adding a controlled amount of dry ice to an acetone bath. The cooled reaction mixture is treated dropwise with nBuLi solution (16.3 mL of a 2.5 M solution in hexanes, 40 mmol) and the reaction is let stir at that −50° C. for 0.5 h. A solution of 5,6-dichloro-nicotinic acid, (3.7 g, 18.5 mmol) in THF (15 mL) is added dropwise to the reaction at −50° C. The reaction is stirred at −50° C. for 0.5 h. The reaction mixture is treated with benzaldehyde (2.5 ml, 24 mmol) dropwise at −50° C. The reaction is stirred at −50° C. for 2 h and warmed to room temperature overnight. The reaction mixture is concentrated to remove solvent and water and ether are added. The aqueous layer is extracted with ether (6×50 ml). The aqueous phase is treated with 1N HCl, until the pH of aqueous layer is ˜6 and is then extracted with ether (3×40 mL.) The aqueous solution is treated with 1N HCl solution until the pH ˜2 and solution is heated at 100° C. overnight. On cooling a white precipitate appeared. The precipitate is filtered off and washed with bicarbonate and air-dried to give the title compound (4.6 g, 89%) as a white solid.

Provenance & Evidence