One-pot Synthesis of 2-Benzyl/2-Allyl Substituted Thiobenzoazoles Using Transition-metal-free Conditions in Water.

A transition-metal-free protocol for the one-pot synthesis of 2-benzyl/2-allyl-substituted thiobenzoazoles in water was developed. The cyclization of 2-aminothiophenols, 2-aminophenols, and 1,2-phenylenediamines with tetramethylthiuram disulfide (TMTD) gave mercapto benzoheterocycles, and the subsequent C-S coupling with benzyl or allyl halides furnished the desired products in good to excellent yields. This method features transition-metal-free conditions with water as a solvent, an easy performance, mild reaction conditions, a wide substrate scope, and good to excellent yields, thus paving an efficient and useful way to establish a library of potentially active drug molecules.