Some rearrangements of β-methyl-β’-carbethoxypyrrole was written by Fischer, H.;Wiedemann, O.. And the article was included in Z. physiol. Chem. in 1926.Name: Ethyl 4-methyl-1H-pyrrole-3-carboxylate This article mentions the following:
β,β’-Disubstituted pyrroles are of especial interest for syntheses in the field of blood and bile pigments. The α-position of the pyrrole ring, however, becomes less reactive when both β-positions are occupied, particularly with respect to condensations with CH2O, H2CO2 and (CHO)2. Introduction of an aldehyde group by treatment with HCN and HCl furnished the starting point for the synthesis of a number of new derivatives Piloty’s 3-methyl-4-carbethoxypyrrole-5-carboxylic acid (I) was converted into 3-methyl-4,5-dicarbethoxypyrrole (II), m. 63°, by esterification with EtOH and HCl; into 3-methyl-4-carbethoxy-5-carbomethoxypyrrole, m. 59°, by esterification with CH2N2; and into 3-methyl-4-carbethoxypyrrole (III), m. 73°, by heating above the m. p. to expel CO2. Treatment of III with anhydrous HCN and HCl in Et2O gave 2-formyl-3-methyl-4-carbethoxypyrrole (IV), m. 121°, and this by reduction with EtONa and (NH2)2 at 150-60° was converted into 2,3-dimethylpyrrole; picrate, m. 146-7°; phenylhydrazone, m. 154°; semicarbazone, m. 224°; azlactone, m. 192°; oxime, m. 167°. The oxime when refluxed with Ac2O and NaOAc gave the nitrile, m. 135°, and an acetylated nitrile. Condensation of III with IV by means of concentrated HCl gave bis-[3-methyl-4-carbethoxypyrryl]methene-HCl (V), m. 195°; free base m. 129°. In like manner a Me derivative of V, m. 218°, was obtained from IV and 2,4-dimethyl-3-carbethoxypyrrole. Saponification of IV with 20% KOH gave 2-formyl-3-methylpyrrole-4-carboxylic acid, m. 255°, and this when heated in vacuo at 190-200° gave 2-formyl-3-methylpyrrole, m. 95°. 2-Acetyl-3-methyl-4-carbethoxypyrrole (VI), m. 117°, was obtained by treatment of III in Et2O with MeCN and HCl and warming the intermediate imine-HCl with H2O. Reduction of VI by means of EtONa and (NH2)2.H2O at 150° gave 2-ethyl-3-methylpyrrole, isolated as the picrate, m. 137°. Saponification of VI gave 2-acetyl-3-methylpyrrole-4-carboxylic acid, m. 272°; this loses CO2 when melted and forms 2-acetyl-3-methylpyrrole, m. 98°. 2-Chloroacetyl-3-methyl-4-carbethoxypyrrole, m. 115°, was prepared by treatment of III with ClCH2CN and HCl and hydrolysis of the intermediate imine-HCl with dilute NH4OH. A dimethyldicarbethoxypyrocoll, m. 168°, was obtained by refluxing I with Ac2O and NaOAc. The hydrazide of I, m. 165°, was prepared by refluxing II in EtOH with (NH2)2.H2O, while further refluxing with excess of the reagent gave pyrryldiketodiazine, which sublimes at 190-310° but does not m. 360°. 3-Methyl-4-carbohydrazidopyrrole-5-carboxylic acid, m. 235°, was obtained by treatment of the K salt of the ester acid with excess of (NH2)2.H2O in EtOH. The following derivatives of the pyrryl-α-acid hydrazide are described: benzoylhydrazide, m. 232°; phenylthiosemicarbazide, m. 185°; condensation product with glyoxal, m. 330°; condensation product with II, m. 221°. The hydrazide of I formed a HCl salt which reacted with NaNO2 to yield the azide, explosive at 80°. Treatment of the latter with MeOH gave Me 3-methyl-4-carbethoxypyrrole-5-carbamate, m. 108°. 3-Methylpyrrole-4,5-dicarboxylic acid, m. 221°, was prepared by saponification of the ester acid. β-Methylpyrrole reacts with MgEtBr and EtOCOCl to yield 2-carbethoxy-3-methylpyrrole, m. 56°, and this when treated with HCN and HCl yields 2-carbethoxy-3-methyl-5-formylpyrrole, m. 107°; semicarbazone, m. 230°. Distillation of the Ba salt of I converts it into 3-methyl-4-carbethoxypyrrole. In the experiment, the researchers used many compounds, for example, Ethyl 4-methyl-1H-pyrrole-3-carboxylate (cas: 2199-49-7Name: Ethyl 4-methyl-1H-pyrrole-3-carboxylate).
Ethyl 4-methyl-1H-pyrrole-3-carboxylate (cas: 2199-49-7) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits, including apples, durians, pears, bananas, pineapples, and strawberries. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Name: Ethyl 4-methyl-1H-pyrrole-3-carboxylate
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics