Synthesis of Organic Carbonates with Alkyl/aryl 4,5-dichloro-6-oxopyridazine-1(6H)-carboxylates and ROH/AlCl₃under Ambient Condition

Abstract

We demonstrated the synthesis of organic carbonates using alkyl/aryl 4,5-dichloro-6-oxopyridazine-1(6H)-carboxylates and alcohol in the presence of aluminum chloride. Alkyl/aryl 4,5-dichloro-6-oxopyridazine-1(6H)-carboxylates were reacted with alcohol in the presence of AlCl 3 in toluene at room temperature to afford the corresponding unsymmetric and symmetric organic carbonates in good to excellent yields. These are efficient and convenient processes. Alkyl/aryl 4,5-dichloro-6-oxopyridazine-1(6H)-carboxylates are solid, stable and non-toxic CO 2 /CO 2 R(Ar) source. It is noteworthy that the reaction is carry out under an ambient and acidic conditions, the easy-to prepare and readily available starting materials and the quantitative isolation of reusable 4,5-dichloropyridazin-3(2H)-one.

Recent Progress in the Chemistry of Pyridazinones for Functional Group Transformations

“…Indeed, the reaction of 2-aminophenol, 1,2-phenylenediamine or 2-mercaptoaniline with 4 (Ar = Ph) enables the synthesis of the corresponding benzo­[ d ]­azol-2­(3 H )-ones in 49–97% yields in one pot. The analogous reaction using 4 for the synthesis of carbonates has been further achieved . The reaction of alcohol derivatives with 4 under Friedel-Craft (i.e., in the presence of AlCl 3 ) and ambient conditions affords symmetric and asymmetric carbonates in good to excellent yields.…”