2‐Aminothiophene. Heterocyclization of benzylthionitriles

Abstract

Synthesis of unstable 2‐aminothiophene by way of its hydrochloride salt has been achieved in excellent yield. The key reaction in the scheme involves a novel heterocyclization of benzylthionitriles, which would appear to have general utility. Spectral and physical properties are tabulated and a possible mechanism is proposed.

One-Pot Syntheses of 2-N-Alkylamino-, 2-N-Phenylamino-, 2-N, N-Dialkylamino-, and 2-N-Alkyl-N-phenylaminothiophenes

“…the ϭNϪCH 3 group and resulting in the very unstable cumulenic system H 2 CϭCϭCϭC(SLi)ϪNϭCH 2 . Another c. Stability of the Thienylamines Synthesized limitation of the scope of our synthetic method concerns the low stability of the product from the reaction of lithiIn contrast to the parent compound 2-aminothiophene [6] , the N-monosubstituted thiophenes 7 obtained by our ated N,N-dimethyl propargylamine 2 [R ϭ (CH 3 ) 2 N] with methyl isothiocyanate (RЈ ϭ CH 3 ) and subsequent hydroly-method seem to be fairly thermostable. Nevertheless, after storage (under nitrogen) for a few days at room temperasis.…”

“…The reaction mained. Like aminothiophene [6] compounds 7 show a high mixtures gradually turned dark-brown upon increasing the temsensitivity towards oxygen. Exposure of the compounds to perature.…”

Intramolecular Reversible Addition Reactions to the Other Groups

“…y-Mercaptonitriles (12A) are transient species during the formation from S-benzylderivatives (11) which cyclize immediately yielding imino- [53] b [29] c [50] 0 , 0…”

“…e [52] dihydrothiophene derivatives (12B) [29,[50][51][52][53]. These isomerize to aminothiophenes (12C) if an a-hydrogen atom is present relative to the C=N bond [51,53].…”

A química do ranelato: aspectos fundamentais da estrutura eletrônica e reatividade

“…Os compostos 2-aminotiofeno e 3-aminotiofeno são compostos aromáticos porém menos estáveis que o tiofeno (Figura 12a) [45] . A instabilidade do 2-aminotiofeno está associada à possibilidade de decomposição desta estrutura em um compostos vítreo marrom e pode ser minimizada por grupos retiradores eletrônicos ligados no anel de 5 membros (Figura 12b) [46,47] . reportada por David L. Eck e Gardner W. Stacy [46] .…”