The author of 《Synthesis of pyrrole-3-carboxylic acids》 were Rapoport, Henry; Willson, Clyde D.. And the article was published in Journal of Organic Chemistry in 1961. Application of 2818-08-8 The author mentioned the following in the article:
When 3-carbethoxy-4-methoxy-Δ3-pyrrolines were refluxed with alkali, elimination of the MeO group occurred and pyrrole-3-carboxylic acids were formed. 1,3-Dicarbethoxy-4-pyrrolidone (69 g.) left 3 hrs. at room temperature with excess CH2N2 in Et2O gave 60 g. 1,3-dicarbethoxy-4-methoxy-Δ3-pyrroline (I), m. 65-6°. Similar treatment of 9.7 g. 1,3-dicarbethoxy-2-methyl-4-pyrrolidone with CH2N2 gave 9.8 g. 1,3-dicarbethoxy-2-methyl-4-methoxy-Δ3-pyrrolidone (II), b1 123-5°. Likewise, 1,2,3-tricarbethoxy-4-pyrrolidone gave 1,2,3-tricarbethoxy-4-methoxy-Δ3-pyrroline (III). I (5 g.) in 60% aqueous MeOH treated at 60° with NaOH solution to pH 11 (after 9 hrs. 100 mole % of alkali had been used, and the pH remained constant after an addnl. 12 hrs.), the solution acidified, extracted with BuOH, and the residue treated with CH2N2 in Et2O 3 hrs. at room temperature gave 3.1 g. 1-carbethoxy-3-carbomethoxy-4-methoxy-Δ3-pyrroline, m. 90-3°. I (12.2 g.) and 50 g. Ba(OH)2.8H2O in 250 ml. H2O refluxed 4 hrs. gave 3 g. pyrrole-3-carboxylic acid (IV), m. 150-50.5°. IV with excess CH2N2 3 hrs. at room temperature gave 90% Me pyrrole-3-carboxylate, m. 86-7°. II (1 g.) and 5 g. Ba(OH)2.8H2O similarly treated gave 310 mg. 2-methylpyrrole-3-carboxylic acid, m. 178-9°; Me ester (95% yield) m. 67-8°. III (7 g.) and 30 g. Ba(OH)2.8H2O refluxed 4 hrs. in 100 ml. H2O and the product isolated as above gave 170 mg. pyrrole-2,3-dicarboxylic acid, m. 220° (decomposition); di-Me ester (36 mg. from 170 mg.) m. 69-71°. The ultraviolet and infrared absorption spectra were given for the above compounds After reading the article, we found that the author used Dimethyl 1H-pyrrole-2,3-dicarboxylate(cas: 2818-08-8Application of 2818-08-8)
Dimethyl 1H-pyrrole-2,3-dicarboxylate(cas: 2818-08-8) belongs to pyrroles. Pyrroles are components of more complex macrocycles, including the porphyrinogens and products derived therefrom, including porphyrins of heme, the chlorins, bacteriochlorins, and chlorophylls. Porphobilinogen, a trisubstituted pyrrole, is the biosynthetic precursor to many natural products such as heme.Application of 2818-08-8
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics