Dimethyl aminoterephthalate → Dimethyl 2-isocyanatoterephthalate

Participants

Reaction Steps

Dimethyl 2-aminoterephthalate (3.0 g, 14.34 mmol) and triphosgene (5.1 g, 17.22 mmol) were dissolved in toluene. Stirring was carried out at 110° C. for 6 hours under reflux to obtain 2-isocyanato-terephthalic acid dimethyl ester. After evaporating solvent, the compound was dissolved in 1,4-dioxane and triethylamine in vacuum state. After adding cyclohexylamine (2.5 mL, 21.5 mmol), stirring was carried out at 90° C. for 60 hours under reflux. After the reaction was completed, the produced solid was filtered with ether to obtain 1.75 g (37%) of 2-(3-cyclohexyl-ureido)-terephthalic acid dimethyl ester having a urea structure.

Provenance & Evidence