Syntheses of cyanothiophenes from halothiophenes was written by Nishimura, Shoji;Imoto, Eiji. And the article was included in Nippon Kagaku Zasshi in 1961.Synthetic Route of C5H2N2O2S This article mentions the following:
2-Iodothiophene (42 g.), 20 g. Cu2(CN)2, and 120 cc. pyridine were refluxed 3 hrs., 5060 cc. pyridine distilled, 150 cc. C6H6 added, and the mixture refluxed 30 min., cooled, and filtered to give 14.3 g. 2-cyanothiophene (I), b21 88-90°. A mixture of 2-bromothiophene (32.6 g.), 20 g. Cu2(CN)2, and 150 cc. quinoline was refluxed 4 hrs., distilled, and treated with HCl to give 11.3 g.I. Similarly, 3-bromothiophene gave 70% 3-cyanothiophene. Similarly, the following cyanothiophenes were obtained (substituent on the starting material, reaction period in hrs., and % yield given): 2,5-BrNO2, 4.0, 32; 2,5INO2, 3.0, 70; 2,3-BrNO2, 4.0, 35; 3,2-BrNO2, 4.0, 54; 3,4-Br-NO2, 4.5, 24; 2,4-BrNO2, 4.5, 20; 2,5-AcI, 4.5, 44; 2,5-AcBr, 7.0, 20; 2,5-AcCl, 7.0, 0; 2,5-BrCO2Me, 7.0, 0. The results indicate that reactivity of halogens is I > Br > Cl and the activating ability of substituents is NO2 Ac > CO2Me. Reactions of 5- acetyl- 2- bromo- 3- nitrothiophene, 2- bromo- 5- methoxycarbonyl-3-nitrothiophene, 2-bromo- 5- carboxy- 3- nitrothiophene, and 2,5-dibromo-3-nitrothiophene yielded 17% 2-acetyl-4-nitrothiophene, 10% 2-methoxycarbonyl-4-nitrothiophene, 15% 2cyano-3-nitrothiophene (II), and 35% II, resp. Hydrolysis of cyano compounds was carried out by heating with concentrated HCl for 2-3 hrs. but II, 3-cyano-2-nitrothiophene, and 3-cyano-4-nitrothiophene were recovered unchanged. In the experiment, the researchers used many compounds, for example, 4-Nitrothiophene-2-carbonitrile (cas: 42137-24-6Synthetic Route of C5H2N2O2S).
4-Nitrothiophene-2-carbonitrile (cas: 42137-24-6) belongs to nitriles. Nitriles are polar, as indicated by high dipole moments. As liquids, they have high relative permittivities, often in the 30s. Nitrile groups in organic compounds can undergo a variety of reactions depending on the reactants or conditions. A nitrile group can be hydrolyzed, reduced, or ejected from a molecule as a cyanide ion.Synthetic Route of C5H2N2O2S
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts