“…1 H NMR (DMSO-d 6 ) δ (ppm), J (Hz): 1.07 (s, 6H, 2xCH 3 ), 2.32 (s, 3H, CH 3 ), 4.77 (sp, 1H, CH), 6.09 (s, 1H, H-3), 6.75 (d, 1H, H-6, J = 8.5), 6.90 (d, 1H, H-5, J = 8.5), 9.14 (s, 1H, NH), 11.07 (s, 1H, OH). 13 (22). 1 H NMR (DMSO-d 6 ) δ (ppm), J (Hz): 0.87 (s, 6H, 2xCH 3 ), 1.84-1.86 (m, 1H, CH), 2.37 (s, 3H, CH 3 ), 3.79 (d, 2H, CH 2 , J = 6.5), 6.14 (s, 1H, H-3), 6.90 (d, 1H, H-6, J = 8.8), 7.49 (d, 1H, H-5, J = 8.8), 8.51 (s, 1H, NH), 10.52 (s, 1H, OH).…”