Zur Reaktion von 2‐Aminothiophen‐3‐carbonitrilen mit Heterocumulenen

Abstract

The Reaction of 2‐Aminothiophene‐3‐carbonitriles with Heterocumulenes. The reaction of 2‐aminothiophene‐3‐carbonitriles (1) with phenyl isothiocyanate does not yield the expected thieno[2,3‐d]pyrimidine derivatives but the substituted dithieno‐[2′,3′:4, 3][2′,3′:8, 9]pyrimido[3, 4‐a]pyrimid‐7‐thiones (4). The compounds 4 also may be synthesized from 1 and thiophosgene. Analogously, from 1 and phenyl isocyanate the substituted dithieno[2′,3′:4, 3][2′,3′:8, 9]pyrimido[3, 4‐a]pyrimid‐7‐ones (9) arise in small yields. They are better obtainable from 1 and phosgene. Carbon disulphide react with 1 in pyridine to form a mixture of the thieno[2, 3‐d]pyrimid‐2, 4‐dithione (10) and the condensed compound 4. The ratio of products depends on the substituents in the 4, 5‐position of 1. The structures are investigated by n.m.r.‐spectroscopy.

Reactions of 2‐amino‐3‐cyano‐4,5,6,7‐tetrahydrobenzo[b]thiophene and 2‐amino‐3‐cyano‐4,7‐diphenyl‐5‐methyl‐4H‐pyrano[2,3‐c] pyrazole with phenylisocyanate, carbon disulfide, and thiourea

“…Treatment of compounds 1a or 2a with carbon disulfide in 10% ethanolic sodium hydroxide solution afforded the thieno [2,3- The structures of compounds 5 and 8 were substantiated from their spectral data and they were rigidly confirmed by mp comparison with that reported [1,3]. However, the structures of compounds 6 and 7 were deduced spectroscopically as well as chemically in the former one.…”

“…It has been reported [1] that 2-amino-3-cyano-4,5,6,7-tetrahydrobenzo [b]thiophene 1a reacted with phenylisocyanate in DMF and carbon disulfide in pyridine to give dithienopyrimidopyrimidinone and thienopyrimidinedithione beside dithienopyrimidopyrimidinethione, respectively. However, Sukumaran and Rajasekharass [2] reported the formation of thienothiazine upon treating 1a with carbon disulfide in pyridine.…”

Synthesis of Thieno[2,3-d]Pyrimidines, Thieno[2,3-d]Triazinones and Thieno[2,3-e]Diazepinones of Anticipated Anti-Cancer Activity

“…A literature survey revealed that an analogous compound was produced under similar reaction conditions. 21 A suggested mechanism for the formation of the title compound is shown in Fig. 3.…”

Preparation and biological properties of 2-thio-containing pyrimidines and their condensed analogs

“…The synthesis of ethyl 2-amino-5-benzoyl-1H-pyrrole-3-carboxylate (55) and its use for the synthesis of 2-thioxopyrimidine-containing condensed derivatives were described in the work by Danswan et al 38 Thus, it was shown that interaction of compound 55 with ethyl isothiocyanate yielded 6-benzoyl-3-ethyl-2-thioxo-2,3-dihydro-1H-pyrrolo- An interesting transformation was published by Gewald and his colleagues. 40 They explored the reaction of 2-aminothiophene-3-carbonitrile and its substituted derivatives 64 with phenyl isocyanate (Scheme 17). It was established that unlike in some previously described similar cases (cf.…”