In organic chemistry, atoms other than carbon and hydrogen are generally referred to as heteroatoms. The most common heteroatoms are nitrogen, oxygen and sulfur. Now I present to you an article called Isolation and characterization of a novel tetrahydro-[2,2′]bipyrrolyl dimer as an impurity from a Knorr reaction, published in 2004-10-31, which mentions a compound: 2199-44-2, mainly applied to malonate pentanedione nitrite Knorr reaction; pyrrole preparation; bipyrrole preparation, Computed Properties of C9H13NO2.
A dimer, tetra-Et 2,2′,3,3′-tetramethyl-1,1′,2,2′-tetrahydro-4H,4’H-2,2′-bipyrrolyl-5,5,5′,5′-tetracarboxylate (I), has been isolated as an impurity from a Knorr reaction for the synthesis of Et 3,5-dimethylpyrrole-2-carboxylate from 2,4-pentanedione and di-Et oximinomalonate in a dissolving zinc reduction The solid-state structure of I was determined by X-ray crystallog. 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.
There are many compounds similar to this compound(2199-44-2)Computed Properties of C9H13NO2. if you want to know more, you can check out my other articles. I hope it will help you，maybe you’ll find some useful information.
Reference:
Thiazolidine – Wikipedia,
Thiazolidine – ScienceDirect.com