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To a solution of 3 -methyl- lH-pyrazole-4-carbaldehyde (1 g, 9.08 mmol) in acetonitrile (10 mL) is added potassium carbonate (1.76 g, 12.71 mmol) and 2,3- difluornitrobenzene (1.73 g, 10.90 mmol) and the mixture is stirred at room temperature overnight. Water is added and the organic phase is extracted with ethyl acetate. Organic layer is dried over sodium sulfate and the solvent evaporated under reduced pressure. The residue is purified by normal phase Isco chromatography using as eluent ethyl acetate/hexane (20-80%) to give a 62% yield of a mixture of regioisomers containing the title compound as major product that is used with no further purification. NMR is consistent with desired structure, although mixture of regiosomers is detected: NMR (MeOD): 9.98 (s, 1H), 8.65 (d, 1H, J= 1.6 Hz), 7.99-7.26 (m, 3H), 2.49 (s, 3H). A mixture of l-(2-fluoro-6-nitro-phenyl)-3 -methyl- lH-pyrazole-4-carbaldehyde (620 mg; 2.49 mmol) (as major compound in a mixture of regioisomers in the pyrazole) and Iron (1.40 g) in ethanol (5.1 mL) and water (5.1 mL) with few drops of acetic acid is heated at 90C for 2h. After that time, it is filtered over celite, and eluted with more ethanol. Mixture is concentrated under vacuum, basified with sodium bicarbonate (saturated aqueous solution) and extracted with dichloromethane. Organic layer is decanted, dried over magnesium sulfate and solvent evaporated under reduced pressure to give 500 mg of the title compound, as major product in a mixture of regioisomers in the pyrazole, that is used without further purification. MS (m/z): 220 (M+l). To a solution of l-(2-amino-6-fluoro-phenyl)-3-methyl-lH-pyrazole-4- carbaldehyde (500 mg, 2.28 mmol) (as major compound in a mixture of regioisomers in the pyrazole) in dichloromethane (15.21 mL), pyridine (553.31 muKappa) is added. Then, methyl chloroformate (194.17 mu) is added dropwise at 0C and the mixture is stirred at room temperature for 30 min. Water is added and the mixture is extracted with dichloromethane. Organic layer is decanted, dried over magnesium sulfate and solvent evaporated under reduced pressure. The residue is purified by normal phase Isco chromatography using as eluent ethyl acetate and hexane to give 418 mg of the title compound. MS (m/z): 278 (M+l). To a solution of methyl N-[3-fluoro-2-(4-formyl-3-methyl-pyrazol-l- yl)phenyl]carbamate (335 mg, 1.2 mmol) (as major compound in a mixture of regioisomers in the pyrazole) in tetrahydrofuran (6 mL) under nitrogen atmosphere and cooled to 0C, sodium hydride (60% in mineral oil) (58.3 mg) is added. Then, methyl iodide (0.4 mL) is added and the reaction mixture is stirred at 0C for 1 hour. After that time, water is added and the mixture is extracted with ethyl acetate. Organic layer is decanted, dried over sodium sulfate and solvent evaporated. The residue is purified by normal phase Isco chromatography using as eluent ethyl acetate and hexane to give 287 mg of the title compound, as major product in a mixture of regioisomers in the pyrazole, that is used without further purification. MS (m/z): 292 (M+l). To a solution of 2-chloro-4,4-difluoro-spiro[5H-thieno[2,3-c]pyran-7,4'- piperidine] (210 mg, 0.75 mmol) in dichloromethane (3.00 mL), methyl N-[3-fluoro-2-(4- formyl-3-methyl-pyrazol-l-yl)phenyl]-N-methyl-carbamate (284.27 mg) (as major compound in a mixture of regioisomers in the pyrazole) is added. The mixture is stirred 10 min at room temperature. Then, sodium triacetoxyborohydride (331.5 mg) is added, and the reaction is stirred at room temperature overnight. The mixture is diluted with dichloromethane and quenched slowly with sodium bicarbonate (saturated solution). The organic phase is then extracted with more dichloromethane, decanted, dried over magnesium sulfate and solvent evaporated under reduced pressure. The residue is purified by normal phase Isco chromatography using as eluent dichloromethane and methanol to give 160 mg of methyl N-[2-[4-[(2-chloro-4,4-difluoro-spiro[5H-thieno[2, 3-c]pyran-7,4'- piperidine]- -yl)methyl]-3-methyl-pyrazol-l-yl]-3-fluoro-phenyl]-N-methyl-carbamate. MS (m/z): 555 (M+l).The tartrate salt is essentially prepared as described in Example 1. MS (m z): 555 (M+l). |
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