Dichloromethane → 62780-15-8

Participants

Reaction Conditions

Reaction Steps

To 5 l of a methylene chloride solution containing 550 g of 1-(2',6'-dichlorophenyl)-2-(2',3'-bis-methoxycarbonylguanidino) ethanol was added 530 ml of triethylamine. The mixture was stirred until a clear solution formed. Mesyl chloride, 160 ml was then added dropwise with stirring at such a rate that the solution temperature did not pass 35° C. The reaction was complete after 30 minutes. One liter of methanol was added to the reaction mass and the resulting mixture filtered. To the filtrate was added 4 l of methanol and a solution of 270 g of sodium hydroxide in 550 ml of deionized water. The mixture was vigorously agitated and heated to about 40° C. for one hour. The reaction solution was then vacuum distilled until approximately 5 l of distillate had been collected. After addition of 8 l of deionized water to the distillation flask, vacuum distillation was continued, collecting 3 l of distillate. The pot residue was cooled to about 20° C. and stirred for about 1 hour. The imidazole product precipitated from the residual reaction solution and was filtered, washed with 3 l of deionized water then 1 liter of methanol. Drying at 65° C. in a vacuum oven gave 403 g of 4,5-dihydro-2-methoxycarbonylamino-5-(2',6'-dichlorophenyl)imidazole, m.p. 231°-232° C. (dec.).

Provenance & Evidence