Pyridine → HCID 21525330, compound

Participants

Reaction Steps

A suspension of 24.6 g (0.1 mole) of N-(methylaminomethyl)-4-nitro-benzamide in 300 ml of water is neutralised at 0°-25°C with 50 ml of 2 normal sodium hydroxide solution (0.1 mole). The neutralised product is filtered off and dried in vacuo. It is then taken up in 150 ml of 1,2-dimethoxyethane and this solution is treated at 0°-25°C over the course of 1 hour with 9.9 g (0.1 mole) of phosgene in 150 ml of 1,2-dimethoxyethane. A solution of 15.8 g (0.2 mole) of pyridine in 150 ml of 1,2-dimethoxyethane is then added over the course of a further hour. Stirring of the reaction mixture is continued for 2 hours and then it is refluxed for 5 hours. After the reaction mixture has cooled, the precipitate which has formed is collected by filtration, the residue is dissolved in methylene chloride and washed first with sodium bicarbonate solution and then with water and dried. The solvent is evaporated and the residue is recrystallised from ethyl acetate to yield 6-(4-nitro-phenyl)-3-methyl-3,4-dihydro-2H-1,3,5-oxadiazin-2-one with a melting point of 153°-154°C (compound 2).

Provenance & Evidence