Yield:81479-48-3 99%

Reaction Conditions:

with pyridine in tetrahydrofuran at 0 - 25; for 0.75 h;

Steps:

1

Intermediate 2; Phenyl (5-tert-butyIisoxazol-3-yl)carbamate; Phenyl chloroformate (52 mL) was added dropwise to a solution of 3-amino-5-tert- butylisoxazole (52.3 g) in THF (1.0 L) and pyridine (60 mL) at O⁰C. When the addition was complete water (500 mL) was added and the reaction mixture stirred for 45 mins while warming to ambient temperature, before extracting into ether (3 x 300 ml). The combined organics were washed with water, brine and concentrated in vacuo, azeotroping with toluene and chloroform to give the title compound as a colourless solid (96.3 g, 99%). ¹H NMR (DMSOd₆) 1.28 (s, 9H), 6.42 (s, IH), 7.18-7.26 (m, 3H), 7.39-7.45 (m, 2H), 11.13 (bs, IH); MS m/e MH⁺ 261.

References:

WO2006/82404,2006,A1 Location in patent:Page/Page column 86