4-(Octylaminosulfonyl)benzoic acid is prepared in the usual way from octylamine and 4-(chlorosulfonyl)benzoic acid. This material is reduced with lithium aluminum hydride in THF in the usual fashion, and purified by chromatography with 1:3 ethyl acetate-dichloromethane to provide 4-(octylaminosulfonyl)benzyl alcohol as a colorless solid in 54% yield. Swern oxidation (DMSO-oxalyl chloride, dichloromethane) of this material provides 4-(octylaminosulfonyl)benzaldehyde as a colorless solid after chromatography. By the method of example 1(A), but using two equivalents of the phosphonium ylide, the aldehyde is chain-extended and converted to the dimethyl acetal, and by the method of example 2 this is condensed with glyoxylic acid to provide the title compound as a colorless solid, mp 223°-224° after recrystallization from ethyl acetate.
