hexylmethyl). The mixed anhydride of trifluoroacetic acid and cyclopentylacetic acid (V. R= cyclopentylmethyl) was prepared by mixing trifluoroacetic anhydride with cyclopentylacetic acid. The crude mixed anhydride reacted with I11 to yield 4-chloro-6- cyclopentylacetylaminobensene-1, 3-disulfonamide. There was no evidence of the other possible product, 4-chloro-6-trifluoroacetylaminobenzene-1, 3-disulfonamide having been ...