Each compound has different characteristics, and only by selecting the characteristics of the compound suitable for a specific situation can the compound be applied on a large scale. 681128-38-1, name is Ethyl 3,3-difluorocyclobutanecarboxylate, This compound has unique chemical properties. The synthetic route is as follows., Formula: C7H10F2O2
Preparation 32: 4-(3-chloro-5-(3,3-difluorocyclobutyl)-4,5-dihydro-1H-pyrazol-1-yl)- 2-methylbenzonitrile; Step 1 : ethyl S-O.S-difluorocvclobutvDacrylate; To a solution of ethyl 3,3-difluorocyclobutanecarboxylate (1.94 g, 11.82 mmol) in dichloromethane (40 ml_) at -78C was added diisobutyl aluminum hydride (13 ml_ of a 1.0M solution in hexanes, 13.0 mmol). The reaction was stirred at -78C for 45 min. Saturated aqueous ammonium chloride (40 ml_) was added, and the resulting mixture stirred overnight at room temperature. The biphasic mixture was filtered through celite. The organic layer was dried over sodium sulfate, filtered and concentrated to give 3,3- difluorocyclobutanecarboxaldehyde which was used immediately without further purification. To a suspension of sodium hydride, 60 wt% dispersion in mineral oil (487 mg, 12 mmol) in tetrahydrofuran at 0C was added triethyl phosphonoacetate (2.4 mL, 12.0 mmol) dropwise. After addition was complete, the mixture was allowed to warm to room temperature, and stirred until the suspension cleared (~10 min.). 3,3- difluorocyclobutanecarboxaldehyde was added as a solution in tetrahydrofuran (10 mL). The resulting solution was stirred at room temperature 4 h. Diethyl ether (40 mL) was added, and the reaction was quenched by addition of saturated aqueous ammonium chloride (20 mL). The organic layer was dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography eluting with a gradient of 0%-5% ethyl acetate in heptane to yield ethyl 3-(3,3- difluorocyclobutyl)acrylate (498 mg, 22%) as a yellow oil. 1 H NMR ( 400 MHz,CHLOROFORM-d) delta ppm 1.30 (3 H, t, J=7.1 Hz), 2.49 (2 H, m), 2.83 (2 H, m), 2.94 (1 H, m), 4.21 (1 H, q, J=7.2 Hz), 5.85 (1 H, dd, J=15.5, 1.3 Hz), 7.00 (1 H, dd, J=15.5, 7.3 Hz).
Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 681128-38-1.
Reference:
Patent; PFIZER INC.; ARHANCET, Graciela Barbieri; CASIMIRO-GARCIA, Agustin; CHEN, Xiangyang; HEPWORTH, David; MEYERS, Marvin Jay; PIOTROWSKI, David Walter; RAHEJA, Raj Kumar; WO2010/116282; (2010); A1;,
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