[3-(4-Bromo-phenyl)-isoxazol-5-yl]-methanol

Synthesis

The general procedure for the synthesis of 5-bromomethyl-3-(4-bromophenyl)-isoxazole from 2-propyn-1-ol and cis-4-bromo-A-chlorobenzaldehyde oxime was as follows: to 4-bromo-N-hydroxybenzenemethanimidoyl chloride (3.5 g, 14.9 mmol) synthesized in Step 2 of the Preparation of Example 6, alkyne-1-ol (2.74 mL, 45 mmol) and triethylamine ( Et3N, 7.7 mL) in dichloromethane (50 mL) and the reaction mixture was stirred at room temperature for 1.5 hours. Upon completion of the reaction, the reaction endpoint was confirmed by TLC. Subsequently, extraction was performed with dichloromethane (500 mL) and water (200 mL), and the organic layer was washed sequentially with water (100 mL x 2) and brine (50 mL). The organic layer was separated, dried with anhydrous magnesium sulfate, and the solvent was removed by filtration under reduced pressure. The residue was purified by silica gel column chromatography using ethyl acetate and hexane as the unfolding solvents to afford the target product 5-bromomethyl-3-(4-bromophenyl)-isoxazole (3-(4-bromophenyl)isoxazol-5-yl)methanol (11e). The yield was 69%.1H NMR (CDCl3, 400MHz) data were as follows: δ 7.66 (d, 2H, J = 2.4Hz), 7.64 (d, 2H, J = 1.6Hz), 6.53 (s, 1H), 4.81 (s, 2H).

References

[1] Journal of Medicinal Chemistry, 2003, vol. 46, # 2, p. 284 - 302
[2] Patent: US2010/63041, 2010, A1. Location in patent: Page/Page column 32
[3] Patent: WO2008/108602, 2008, A1. Location in patent: Page/Page column 51; 31-32