Pyridine → HCID 21249770, compound

Participants

Reaction Steps

In a 0.3-l four-necked flask equipped with a dropping funnel, a reflux condenser, a thermometer and a mixing blade were placed 18.0 g (0.0666 mol) of N-(3,5-dinitrophenyl)-N-(2-hydroxyethyl)urea (compound 11) and 5.27 g (0.0666 mol) of pyridine. Thereto was added 150 ml of dichloromethane. The mixture was stirred and became a yellow suspension. While the flask was being cooled with ice water, the flask contents were stirred. Thereto was dropwise added 8.52 g (0.0799 mol) of isobutyryl chloride. After the dropwise addition, the flask was immersed in an oil bath of 40° C. and the flask contents were stirred for 1 hour. Then, the flask contents were cooled to room temperature. Thereto was added 50 ml of water, and the mixture was stirred for several minutes. All the flask contents were transferred into a separating funnel for separation of the aqueous layer. The organic layer taken out was returned to the separating funnel. Thereto was added a 5% aqueous sodium carbonate solution, followed by mixing. The lower layer (organic layer) was taken out and dried over anhydrous magnesium sulfate. From the dried solution was removed dichloromethane by distillation by the use of an evaporator, whereby a solid was separated. The solid was recrystallized from a 2:1 mixed solvent consisting of methanol and water to obtain 2-(3,5-dinitrophenylureido)ethyl isobutyrate (compound 12) as a yellow powder. Yield: 20.4 g (90%) Melting point: 89-92° C.

Provenance & Evidence