123770-62-7, Ethyl 5-(hydroxymethyl)isoxazole-3-carboxylate is a Isoxazoles compound, ?involved in a variety of chemical synthesis. Rlated chemical reaction is continuously updated
A solution of ethyl chlorooximidoacetate (15 g, 0.1 mol) in CH2Cl2 is added dropwise over 4 h to propargyl alcohol (29 mL, 0.5 mol) and Et3N (14 mL, 0.1 mmol) in 200 mL CH2Cl2. When the addition is complete, the reaction mixture is concentrated and triturated with Et2O. The solid is filtered and the organics are concentrated again. The remaining oil is chromatographed over silica gel (EtOAc/Hex:20/80) to give ethyl 5-(hydroxymethyl)isoxazole-3-carboxylate an oil. The remaining propargyl alcohol is removed by azeotroping from n-heptane to yield 11.7 g (69% yield). 1H NMR (400 MHz, CDCl3) delta 6.69, 4.84, 4.44, 1.42. To a solution of ethyl 5-(hydroxymethyl)isoxazole-3-carboxylate (4.0 g, 23 mmol) and TBSCl (3.7 g, 25 mmol) in DMF is added Et3N (3.4 mL, 24 mmol) dropwise over 20 minutes. The reaction is allowed to stir for 30 minutes after which it is diluted with EtOAc (300 mL), washed with 1 M HCl (3¡Á100 mL), 5% CuSO4 (2¡Á50 mL) and concentrated in vacuo to yield 6.91 g (>100% yield) of oily material with visible TBS impurities by NMR. 1H NMR (400 MHz, CDCl3) delta 6.49, 4.69, 4.31, 1.30, 0.80, 0.02. A mixture of ethyl-5-({[tert-butyl(dimethylsilyl)]oxy}methyl)isoxazole-3-carboxylate (1.68 g, 5.9 mmol) and hydrazine hydrate (044 g, 8.8 mmol) in ethanol (30 mL) is heated to 60 C. for 4 h. The mixture is cooled to RT and the solvents are removed in vacuo to yield 1.40 g (87% yield) of orange crystals. 1H NMR (400 MHz, DMSO-d6) delta 9.95, 6.61, 4.74, 4.51, 0.79. A mixture of 5-({[tert-butyl(dimethyl)silyl]oxy}methyl)isoxazole-3-carbohydrazide (1.32 g, 4.9 mmol) in concentrated hydrochloric acid (40 mL) is cooled to 0 C., followed by a dropwise addition of aqueous NaNO2 (0.42 g, 6.1 mL), maintaining the temperature below 5 C. After 1 h, the yellow mixture is diluted with water (100 mL) and extracted with EtOAc (3¡Á50 mL). Organics are dried (MgSO4) and concentrated in vacuo to yield 0.93 g (>100% yield) of 5-(hydroxymethyl)isoxazole-3-carbonylazide as tan crystals. 1H NMR (400 MHz, DMSO-d6) delta 6.82, 4.64. Example 611 is obtained according to Method F. Yield 20%. MS (ESI) for C13H14BrN3O5 m/z 372 (M-H)-.
123770-62-7, The synthetic route of 123770-62-7 has been constantly updated, and we look forward to future research findings.
Reference£º
Patent; Piotrowski, David W.; Rogers, Bruce N.; McWhorter JR., William W.; Walker, Daniel Patrick; Corbett, Jeffrey W.; Groppi JR., Vincent E.; Rudmann, Daniel G.; US2003/236287; (2003); A1;,
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