As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 69716-28-5, name is N-Hydroxypicolinimidoyl chloride, molecular formula is C6H5ClN2O, The compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below. Formula: C6H5ClN2O
1-B. Alternative Preparation of ethyl 3-(pyridin-2-yl)-4-(trifluoromethyl)isoxazole-5- carboxylate; [00112] To a solution of (Z)-ethyl 2-bromo-4,4,4-trifluorobut-2-enoate (1.58 g, 6.39 mmol) and (E,Z)-N-hydroxypicolinimidoyl chloride (2.0 g, 12.8 mmol) in ethyl acetate (10 mL) was added indium (III) chloride (0.283 g, 1.28 mmol). The resulting mixture was stirred for 30 minutes under nitrogen, and then potassium hydrogen carbonate (0.959 g, 9.58 mmol) was added. The reaction mixture was stirred for 14 h. The mixture was filtered, and the solid was rinsed with ethyl acetate (10 ml). The filtrate was washed with a saturated aqueous solution of ammonium chloride (10 mL), washed with brine (10 mL), and concentrated. The residue was purified by flash silica gel chromatography using EtOAc/Hexane as the solvent. The fractions containing the product were pooled and concentrated to give the product as an oil (1.15g, 63% yield) as a mixture of the desired isomer, ethyl 3-(pyridin-2-yl)-4- (trifluoromethyl)isoxazole-5-carboxylate and the undesired isomer, ethyl 3-(pyridine- 2-yl)-5-(trifluoromethyl)isoxazole-4-carboxylate in a ratio of approximately 30: 1. MS m/e 287.02 (M+H+); 1H NMR (DMSO, 400 MHz) delta 8.73 (d, J = 4.0 Hz, IH), 8.01(m, IH), 7.87(d, J = 8.0 Hz, IH), 7.65(m, IH), 4.53 (q, J = 8.0 Hz, 2H,), 1.46 (t, J = 8.0 Hz, 3H); HPLC (XBridge 5mu Cl 8 4.6×50 mm, 4 mL/min; Solvent A: 10 % MeOH/water with 0.2 % H3PO4; Solvent B: 90 % MeOH/water with 0.2 % H3PO4, gradient with 0-100 % B over 4 minutes): 3.57 minutes.
With the rapid development of chemical substances, we look forward to future research findings about 69716-28-5.
Reference:
Patent; BRISTOL-MYERS SQUIBB COMPANY; PITTS, William, J.; DYCKMAN, Alaric, J.; SPERGEL, Steven, H.; WATTERSON, Scott, Hunter; WO2010/85582; (2010); A1;,
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