“…The solvent is evaporated and the residue dried in vacuo to give 13.04 g (98.0%) of 3 as a colorless, partially crystallized oily substance. IR (film): 1670, 2940, 3000, 3400 cm -1 ; MS m/z (%): 324 (M+, 10), 240 (1.74), 190 (5.25), 134 (74.6), 84 (100); 1 H-NMR: 1.41-1.43 (d, 2H, J =5), 1.53-1.60 (m, 4H, J =5), 1.90 (s, 1H), 2.01-2.09 (m, 2H, J =7), 2.37 (s, 4 H), 3.44 (s, 2H), 3.51-3.57 (m, 2H, J =7), 4.06 (s, 2H), 4.07-4.11 (t, 2H, J =7), 6.77-6.80 (dd, 1H, J =8), 6.90-6.92 (d, 2H, J =8), 7.19-7.24 (t, 1H, J = 8) [ 2 ].…”