A Practical,Water‐Soluble,Ionic Scavenger for the Solution‐Phase Syntheses of Amides

A new ionic, water‐soluble scavenger for acyl chlorides, 1‐(2‐aminoethyl)pyridinium bromide ( 1 ), has been investigated. Compound 1 was used for the rapid and simple purification of a series of benzamides and sulfonamides (Table) obtained by solution‐phase synthesis from the corresponding amines (Scheme). The inexpensive scavenger, which can be prepared on large scale, was shown to readily ‘eliminate’ excess acyl chlorides (reagent) by simple aqueous extraction. The amides purified in this way were obtained in excellent yields and purities (Table), which makes 1 a versatile new reagent, especially for the combinatorial solution‐phase synthesis of amide libraries.