合成路线1

The cyclization of phenacyl bromide (I) with acetamide (II) by heating at 130 C gives 2-methyl-5-phenyloxazole (III), which is brominated with NBS in CCl4 to yield the dibromo derivative (IV). The condensation of (IV) with cyclopentylmethylmagnesium bromide (V) by means of Li2CuCl4 affords 4-bromo-2-(2-cyclopentylethyl)-5-phenyloxazole (VI), which is debrominated by hydrogenation with H2 over Pd(OH)2 in methanol, providing 2-(2-cyclopentylethyl)-5-phenyloxazole (VII). The sulfonation of the phenyl ring of (VII) with chlorosulfonic acid gives the sulfonyl chloride (VIII), which is condensed with the aniline derivative (IX) by means of pyridine in dichloromethane to yield the sulfonamide (X). Finally, elimination of the Boc protecting group of (X) by means of HCl in methanol affords the target compound.