1H NMR 400 MHz (CDCl3): δ ppm 10.85 (br. s, 1H, COOH), 7.27, 7.12 (2 × d, 4JHH = 2 Hz, 1H, ArH), 4.70 (br. S, 1H, OH), 3.74 (s, 3H, OCH3), 1.37 (s, 9H, C(CH3)3)
13C{1H} NMR 100 MHz (CDCl3): δ ppm 175.0 (COOH), 156.9, 151.2 , 139.9 , 124.2 (Ar), 123.9, 108.8 (ArH), 55.7 (OCH3), 35.1 (C(CH3)3), 29.3 (C(CH3)3)
EA: found (calc) C: 64.31 (64.27), H: 7.07 (7.19), N: 0.13 (0.00)
MS (ESI): m/z 223 (M+)