With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.1136-45-4,5-Methyl-3-phenylisoxazole-4-carboxylic acid,as a common compound, the synthetic route is as follows.
To a solution of 1.5 g of 5-methyl-3-phenyl-4-isoxazolecarboxylic acid in 50 ml of anhydrous tetrahydrofuran stirred at -78C under N2 atmosphere, 5.9 ml of a 2.5M solution of n-butyl lithium in n-hexane was added and the solution was stirred at -78C for 2 hours. Afterwards, 0.89 ml of benzyl bromide was added at -78C and the solution stirred at room temperature for 2 hours. After overnight resting, the solution was poured into water (300 ml), acidified with 1N hydrochloric acid and extracted with ethyl acetate (2 ? 200 ml). The combined organic layers were washed with water, dried (sodium sulphate) and the solvents were evaporated to dryness. The solid residue was washed with petroleum ether to give 1.82 g (84%) of the title compound as an amorphous solid.1H-NMR (200MHz, CDCl3, delta): 9.20-11.80, br, 1H, COOH; 7.10-7.90, m, 10H, phenyl CHs; 3.45, t, 2H, CH2CH2Ph; 3.10, t, 2H, CH2CH2Ph., 1136-45-4
As the paragraph descriping shows that 1136-45-4 is playing an increasingly important role.
Reference£º
Patent; Leonardi, Amedeo; EP1226131; (2003); B1;,
Isoxazole – Wikipedia
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