ASISCHEM A03574

73781-88-1

110099-94-0

General procedure for the synthesis of 2-(methylthio)pyrimidine-5-carboxylic acid from ethyl 2-(methylthio)pyrimidine-5-carboxylate: Synthesis Example 29; Synthesis of Compound 167; Ethyl 2-(methylthio)-5-pyrimidinecarboxylate (1 g, 5 mmol) was dissolved in methanol (15 mL). 1N sodium hydroxide solution (6 mL) was added and the reaction mixture was stirred for 1 hour. Methanol was removed by rotary evaporator and concentrated. Hydrochloric acid (500 μL) was added and the resulting precipitate was filtered, washed with water and dried under vacuum to give 811 mg (95% yield) of the target product. The resulting pyrimidine carboxylic acid was coupled with 4-fluoroaniline using EEDQ (as described in Synthesis Example 1) to give 911 mg (73% yield) of pyrimidine formamide intermediate. The thiomethyl ether portion of pyrimidine formamide (800 mg, 3.1 mmol) was oxidized with m-chloroperoxybenzoic acid (530 mg, 3.1 mmol) in acetonitrile (150 mL) for 1 hr at room temperature, and the resulting precipitate was filtered and dried under vacuum to give 300 mg (35% yield) of the oxidized product. The crude product (300 mg) was dissolved in anhydrous N,N-dimethylformamide (20 mL) and sodium sulfide (124 mg, 2 mmol) was added. The reaction mixture was gently refluxed for 2 h. Ethyl acetate (100 mL) was subsequently added and the organic layer was washed with water. The organic solvent was removed by rotary evaporator and the 6-mercapto-pyrimidinecarboxamide intermediate was purified by preparative HPLC to give 18 mg of product. Finally, alkylation of 6-mercapto-pyrimidinecarboxamide with 2-bromomethyl-phenylboronic acid using Method B afforded 10 mg (36% yield) of compound 163 as a white solid.ESI-MS m/z = 384.0 [M + H]+.