A mixture of 1-benzyl-1,2,3,4-tetrahydroquinolin-7-ol (824 mg, 3.44 mM) and triethylamine (0.6 mL) in dry tetrahydrofuran (THF, 5 ml) was stirred for half an hour under nitrogen atmosphere at room temperature (35° C.). To the stirred reaction mixture, p-tolyl isocyanate (651 mg/ml, 5.16 mM) was added at once and then the reaction mixture was further stirred for 72 hours under N2 atmosphere at RT. The reaction mixture was concentrated under vacuum and then was quenched with distilled water followed by the extraction with chloroform (3×15 mL). The combined fractions of chloroform was again washed with water and dried over sodium sulphate. Further concentration of chloroform fraction under vacuum afforded the crude product, which was finally crystallized with methanol-ether (1:5) to give 8b as solid. Yield: 1.023 g, 79.77%.
