Synthesis
Step A Synthesis of 3,5-dimethylisoxazol-4-amine: 12.00 g (84.44 mmol) of 3,5-dimethyl-4-nitroisoxazole was dissolved in 430 ml of water and 106.15 g (1.984 mol) of ammonium chloride was added. At 4°C, 46.93 g (7.17 mol) of zinc powder was added in batches over a period of 2 hours. Upon completion of the reaction, ethyl acetate was added to the reaction mixture for extraction and the organic phase was filtered through diatomaceous earth to remove solid impurities. The organic layer was dried with anhydrous magnesium sulfate and the solvent was removed by distillation under reduced pressure to afford 3,5-dimethylisoxazol-4-amine in 86% (8.10 g) yield. The product was characterized by 1H-NMR (300 MHz, CDCl3): δ= 2.20 (s, 3H) ppm; 2.28 (s, 3H) ppm; 2.51 (wide s, 2H) ppm.
References
[1] Helvetica Chimica Acta, 1991, vol. 74, # 3, p. 531 - 542
[2] Journal of the Chemical Society, 1921, vol. 119, p. 702
[3] Gazzetta Chimica Italiana, 1941, vol. 71, p. 327,336
[4] Patent: US2003/187028, 2003, A1
[5] Patent: US2002/82264, 2002, A1
