The synthesis and carbon-13 NMR spectra pyrrolothiazoles and their precursors. Bromine-induced cyclization of pyrrolylthioureas was written by Grehn, Leif. And the article was included in Chemica Scripta in 1979.Quality Control of Ethyl 4-nitro-1H-pyrrole-2-carboxylate This article mentions the following:
Several differently substituted pyrrolylthiourea derivatives (e.g. I) have been prepared by the action of acyl isothiocyanates on the corresponding aminopyrroles. Bromine-induced ring closure of selected pyrrolylthioureas in acetic acid or tri-Me phosphate yielded 3 possible isomers of the hitherto unknown pyrrolothiazoles (e.g. II). This reaction has wide applicability. 13C NMR parameters were determined for all new compounds and the direct 13C-1H coupling constants in the pyrrole moiety were utilized to distinguish α- and β-carbons. In the experiment, the researchers used many compounds, for example, Ethyl 4-nitro-1H-pyrrole-2-carboxylate (cas: 5930-92-7Quality Control of Ethyl 4-nitro-1H-pyrrole-2-carboxylate).
Ethyl 4-nitro-1H-pyrrole-2-carboxylate (cas: 5930-92-7) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Esters are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility.Quality Control of Ethyl 4-nitro-1H-pyrrole-2-carboxylate
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics