The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《A modified Knorr pyrrole synthesis》. Authors are MacDonald, S. F.; Stedman, R. J..The article about the compound:Ethyl 3,5-Dimethyl-2-pyrrolecarboxylatecas:2199-44-2,SMILESS:O=C(C1=C(C)C=C(C)N1)OCC).Name: Ethyl 3,5-Dimethyl-2-pyrrolecarboxylate. Through the article, more information about this compound (cas:2199-44-2) is conveyed.
Isonitrosoacetoacetic ester reacts with p-AcCH2SO2C6H4Me, under the conditions of the Knorr pyrrole synthesis, to yield 4% 2,4-dimethyl-3-(p-toluenesulfonyl)-5-carbethoxypyrrole (I), m. 185-6°. When I is refluxed 4 hrs. with W-6 catalyst in absolute EtOH, 2,4-dimethyl-5-carbethoxypyrrole, m. 123-4°, is formed.
From this literature《A modified Knorr pyrrole synthesis》,we know some information about this compound(2199-44-2)Name: Ethyl 3,5-Dimethyl-2-pyrrolecarboxylate, but this is not all information, there are many literatures related to this compound(2199-44-2).
Reference:
Thiazolidine – Wikipedia,
Thiazolidine – ScienceDirect.com