Efficient Route for the Synthesis of New Dinaphthosulfoxide Aza Crowns Using Ethyleneglycol Under Microwave (MW) Irradiation: Macrocyclization is Preferred to Oligomerization Under MW Irradiation

Abstract

New dinaphthosulfoxide aza crowns were prepared from the corresponding dinaphthosulfoxide diester and diamines under reflux conditions (conventional heating) and microwave (MW) irradiation. These reaction routes were used for the synthesis of a series of aza crowns, such as dinaphthosulfide, dinaphthosulfone, dibenzosulfide, and dibenzosulfoxide. The synthesis of aza crowns under MW irradiation in comparison with conventional heating has several advantages, such as shorter reaction times, simpler reaction conditions, and the use of ecofriendly solvents, higher yields, and regioselectivity. In the MW synthesis, macrocyclization is preferred to oligomerization, and thus, the yields of byproducts are low.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

GRAPHICAL ABSTRACT