Eco-friendly and efficient catalyst-free synthesis of N -sulfonylimines from sulfonamides and aldehydes: crucial role of Al 2 O 3 as a reusable dehydrating agent.

A green synthetic method for the synthesis of N -sulfonylimines was developed involving the straightforward condensation of sulfonamides with aldehydes under green and catalyst-free conditions, mediated by neutral Al 2 O 3 as an efficient and reusable dehydrating agent. N -Sulfonylimines were produced in high yields and purity under simple experimental procedures.