Treatment of N-Boc-prolinol (I) with p-toluenesulfonyl chloride and pyridine afforded tosylate (II), which was condensed with the sodium salt of phenol (III) to produce ether (IV). Acid cleavage of the Boc protecting group of (IV) then gave pyrrolidine (V). Sulfonyl chloride (VII) was prepared by chlorination of the sodium salt of 5-isatinsulfonic acid (VI) with POCl3 in tetramethylenesulfone. Acylation of pyrrolidine (V) with acid chloride (VII) gave sulfonamide (VIII). Finally, the isatin nitrogen atom was methylated employing iodomethane in the presence of K2CO3.

Treatment of N-Boc-prolinol (I) with p-toluenesulfonyl chloride and pyridine afforded tosylate (II), which was condensed with the sodium salt of phenol (III) to produce ether (IV). Acid cleavage of the Boc protecting group of (IV) then gave pyrrolidine (V). Sulfonyl chloride (VII) was prepared by chlorination of the sodium salt of 5-isatinsulfonic acid (VI) with POCl3 in tetramethylenesulfone. Acylation of pyrrolidine (V) with acid chloride (VII) gave sulfonamide (VIII). Finally, the isatin nitrogen atom was methylated employing iodomethane in the presence of K2CO3.

Treatment of N-Boc-prolinol (I) with p-toluenesulfonyl chloride and pyridine afforded tosylate (II), which was condensed with the sodium salt of phenol (III) to produce ether (IV). Acid cleavage of the Boc protecting group of (IV) then gave pyrrolidine (V). Sulfonyl chloride (VII) was prepared by chlorination of the sodium salt of 5-isatinsulfonic acid (VI) with POCl3 in tetramethylenesulfone. Acylation of pyrrolidine (V) with acid chloride (VII) gave sulfonamide (VIII). Finally, the isatin nitrogen atom was methylated employing iodomethane in the presence of K2CO3.