Hydrochloric Acid → 4-[(3-Chloro-4-fluorophenyl)amino]-5,6,7,8-tetrahydrothieno[2,3-b:5,4-c']dipyridine-3-carbonitrile

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Reaction Conditions

Reaction Steps

tert-Butyl 4-[(3-chloro-4-fluorophenyl)amino]-3-cyano-5,8-dihydrothieno[2,3-b:5,4-c′]dipyridine-7(6H)-carboxylate from Example 54A (250 mg, 0.365 mmol) was dissolved in 2-propanol (2 mL), and 4 M gaseous hydrogen chloride in dioxane (0.18 mL, 0.72 mmol) was added. The mixture was stirred at 80° C. for 1.5 h. The solvent was removed, and the residue was treated with 1 M aqueous sodium hydroxide solution (5 mL). The precipitate was collected by suction filtration, washed with water and dried in vacuo to yield 138 mg (99%) of the title compound.

Provenance & Evidence