p-Toluenesulfonic acid monohydrate → HCID 9903890, compound

Participants

Reaction Steps

To a solution of the diamine of Step A (6 g) in dioxane (100 mL) under nitrogen was added N,N′-thiocarbonyl-di-1,2,4-triazole (4.5 g). After stirring at room temperature for 3 hours, para-toluene sulfonic acid monohydrate was added in one portion (9.5 g) and the mixture was heated at reflux for 8 hours. Additional para-toluene sulfonic acid monohydrate was added (1 g) and reflux was resumed for another 2 hours. The mixture was cooled and diluted with ethyl acetate. The precipitate was collected and washed with ethyl acetate. The combined filtrates were washed with brine, dried over magnesium sulfate, and evaporated to dryness. The residue was dissolved in dichloromethane and absorbed onto a column of Merck-60 flash silica gel. Elution with 20% ethyl acetate in hexane provided the title compound as a white crystalline solid (5.26 g, 74.6%). The material was slurried in hexane-ether, sonicated and collected to provide 4.91 g of pure product, m.p. 147-149° C.

Provenance & Evidence