1005206-17-6

1095822-17-5

1005206-17-6

Synthesis of compound 1. A solution of lithium hydroxide (LiOH, 0.236 g, 10.2 mmol) in water (4 mL) was slowly added dropwise to a solution of methyl 7H-pyrrolo[2,3-d]pyrimidine-4-carboxylate (1.4 g, 7.9 mmol) in tetrahydrofuran (THF, 20 mL) at 0 °C. The reaction mixture was stirred at 0 °C for 1 hour. Subsequently, the reaction solution was acidified with concentrated hydrochloric acid to pH 2. THF was evaporated off under reduced pressure and the remaining aqueous solution was cooled to 0 °C. The reaction was purified by filtration. The precipitated white solid was collected by filtration and dried under vacuum to afford 7H-pyrrolo[2,3-d]pyrimidine-4-carboxylic acid (Compound 1, 1.1 g, 85% yield). The product was characterized by 1H NMR (200 MHz, DMSO-d6): δ= 12.80 (broad peak, 1H), 8.95 (single peak, 1H), 7.87 (double peak, J = 2.8 Hz, 1H), 6.96 (double peak, J = 2.8 Hz, 1H). The mass spectrum (MS) showed m/z 164 [M + H]+.