6-Bromo-4-hydroxy-pyrazolo[1,5-a]pyridine-3-carbonitrile

Uses

6-Bromo-4-hydroxy-pyrazolo[1,5-a]pyridine-3-carbonitrile is a pharmaceutical intermediate used in the preparation of Selpercatinib, an FDA-approved drug for the treatment of RET-positive advanced non-small cell lung cancer (NSCLC), thyroid cancer and certain other cancers

Synthesis

At room temperature, add 6-bromo-4-methoxypyrazolo[1,5-a]pyridine-3-carbonitrile (50g, 198.36mmol) and water (16.5mL, 916mmol) in a 1L single-neck flask in sequence, Sodium hydroxide (16.03g, 396.8mmol), DMA (500mL), stirred at room temperature for 5min, then transferred to 0°C, slowly added dodecanethiol (97mL, 397mmol), after the addition, the reaction was moved to 45°C overnight. Pour the reaction solution into 3L ice water, slowly add saturated citric acid water to adjust the PH=5, stir for half an hour, and then stand still filter, wash the filter cake with water and petroleum ether several times, and dry at 60°C to obtain 44.1g of yellow solid 6-Bromo-4-hydroxy-pyrazolo[1,5-a]pyridine-3-carbonitrile (6-Bromo-4-hydroxypyrazolo[1,5-a]pyridine-3-carbonitrile).