Acetic Acid → Dimethyl 2-(carbamoylamino)benzene-1,4-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

To a 1 L flask charged with 2-aminoterephthalic acid dimethyl ester (29.4 g, 141 mmol) was added AcOH (160 mL) and the suspension heated to 60° C. until a solution was formed. A solution of potassium cyanate (23.4 g, 288 mmol) in water (50 mL) was then added to the stirred solution at 60° C. Effervescence was seen and a white ppt crashed out immediately, hindering stirring. AcOH was added (70 mL) to aid stirring and the suspension was stirred at 75° C. for 7 hrs. Another 1 eq of cyanate added portion wise (dry). More effervescence was seen and the reaction left for 16 hours at 70° C. The reaction was cooled to 0° C. and the product ppt was filtered off, the flask washed with water to get all product out. The material was washed with water (150 mL) and air dried o/n under vacuum. The crude product was suspended in MeOH (300 mL) and stirred under reflux for 1 hour. The suspension was cooled to room temperature and filtered. The product was washed with cold MeOH (300 mL) and ether and dried in vacuo to afford the title compound as a white solid, 31.5 g, 89%. 1H NMR (400 MHz, DMSO-D6) δ ppm 9.71 (1H, s) 8.97 (1H, s) 7.98 (1H, d, J=8.08 Hz) 7.46-7.57 (1H, m) 6.73 (2H, s) 3.88 (6H, s).

Provenance & Evidence