Sodium Hydroxide → 3-(7-(3,4-Dimethoxyphenylamino)thiazolo[5,4-d]pyrimidin-5-yl)benzoic acid

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Reaction Steps

To a stirred solution of 3-[7-(3,4-dimethoxy-phenylamino)-thiazolo[5,4-d]pyrimidin-5-yl]-benzoic acid methyl ester (0.85 g, 2 mmol) in 20 mL of THF and 20 mL of methanol was added a solution of NaOH (0.08 g, 20 mmol) in 2 mL of water at room temperature. Then the reaction was stirred at this temperature for 16 hours. The solvent was evaporated and the residue was suspended in 50 mL of THF, then treated by 6N HCl until pH=3. The solvent was evaporated and then dissolved in 30 mL of THF, filtered. The filtrate was evaporated to give 3-[7-(3,4-dimethoxy-phenylamino)-thiazolo[5,4-d]pyrimidin-5-yl]-benzoic acid (0.8 g, 97.5%) as a yellow solid. 1H NMR (300 MHz, DMSO): δ 13.15 (s, 1H), 10.18 (s, 1H), 9.38 (s, 1H), 8.98 (s, 1H), 8.61 (d, 1H, J=8.1 Hz), 8.06 (d, 1H, J=7.5 Hz), 7.84 (d, 1H, J=2.4 Hz), 7.64 (t, 1H, J=7.8 Hz), 7.42 (dd, 1H, J1=8.7 Hz, J2=2.1 Hz), 6.98 (d, 1H, J=8.7 Hz), 3.82 (s, 3H), 3.77 (s, 3H). LC-MS: 409 [M+H]+, 839 [2M+Na]+, tR=1.74 min. HPLC: 98.38% at 214 nm, 97.29% at 254 nm, tR=3.44 min.

Provenance & Evidence