[sup.1]H NMR (DMSO-2 drops TFA) ([delta] ppm): 13.32 (s, 1H, C[O.sub.2]H), 8.28 (s, 1H, Ar-C-OH), 8.25 (s, 1H, CONH), 2.50 (s, 1H, CSNH), 7.60 (d, 2H, Ar-H), 7.40 (d, 2H, Ar-H), 7.33 (s, 1H, Ar-H), 7.37 (s, 1H, ethylene), 6.89 (s, 1H, ethylene), 4.16 (s, 1H, methane), 2.99 (s, 1H, methylene), 2.97 (s, 1H, methylene).
1H NMR (DMSO-2 drops TFA) ([delta] ppm): 12.89 (s, 1H, C[O.sub.2]H), 12.57 (s, 1H, C[O.sub.2]H), 8.33 (s, 1H, CONH), 2.00 (s, 1H, CSNH), 7.60 (d, 2H, Ar-H), 7.40 (d, 2H, Ar-H), 7.33 (s, 1H, Ar-H), 7.37 (s, 1H, ethylene), 6.89 (s, 1H, ethylene), 3.93 (s, 1H, methane), 2.33 (d, 2H, methylene), 2.05 (d, 2H, methylene).