dc.identifier.citation | Thompson, A., Y. Alattar, CS Beshara, RK Burley, et al. 2004. "Isolation and characterization of a novel tetrahydro-[2,2 ']bipyrrolyl dimer as an impurity from
a Knorr reaction." Journal of Heterocyclic Chemistry 41(5): 777-781. | en_US |
dc.description.abstract | A novel dimer, tetraethyl
2,2',3,3'-tetramethyl-1,1',2,2'-tetrahydro-4H,4'H-2,2'-bipyrrolyi-5,5,5',5'-tetracarboxylate, has
been isolated as an impurity (0.4% yield) from a Knorr reaction for the synthesis of ethyl
3,5-dimethylpyrrole-2-carboxyl ate from 2,4-pentanedione and diethyl oximinomalonate in a dissolving
zinc reduction. The solid-state structure of this novel dimer was determined by X-ray
crystallography. Knorr reactions typically rely upon the requisite pyrrole being the only
water-insoluble crystalline material present in the reaction mixture, and so work-up and
purification procedures for Knorr reactions should be monitored carefully given the
water-insolubility of this dimer. Investigations regarding mechanistic implications and reductive
dimerization are underway. | en_US |