“…The catalyst and other solid wastes were removed by filtration. The combined organic layer was dried over anhydrous MgSO 4 and concentrated in vacuo to furnish the products 17 Á 24, which were purified by recrystallization in ethanol. 1 H NMR spectrum, two broad singlets, one at 9.85 ppm due to labile NH proton and another at 11.48 ppm due to OH proton disappeared; 13 1 H NMR spectrum, two broad singlets, one at 9.84 ppm due to labile NH proton and another at 11.57 ppm due to OH proton disappeared; 13 1 H NMR spectrum, two broad singlets, one at 9.92 ppm due to labile NH proton and another at 11.51 ppm due to OH proton disappeared; 13 1H, s, H 3 ), 7.25Á8.80 (15H, m, H arom ), 9.97 (1H, bs, NH); in the D 2 O-exchanged 1 H NMR spectrum, a broad singlet at 9.97 ppm due to labile NH proton disappeared; 13 C NMR (d ppm): 13.8 CH 2 CH 3 at C-1, 35.1 C-5, 43.8 C-6, 59.9 CH 2 CH 3 at C-1, 58.7 C-1, 115.5 C-3, 169.2 C 0O at C-1, 158.7 C-2, 123.1Á128.8 ÁC arom , C-4 carbon may be merged with ÁC arom , 129.5, 132.7, 133.6, 134.3, 141.5, 149.5 ipso carbons.…”