“…The crude product was purified by column chromatography using a mixture of ethyl acetate/hexane of a volume ratio of 2:3 as the eluent. A white solid of about 3.00 g was obtained, Yield, 55% 1. H NMR (400 MHz, CDCl 3 ) δ (ppm): 6.77 (dd, 4H, J = 9.2 Hz, Ar-H), 4.50 -4.40 (m, 1H), 4.20 -4.10 (m, 1H,), 4.03 -3.98 (m, 1H), 3.93 -3.85 (m, 2H), 1.46 (s, 3H), 1.40 (s, 3H).…”