Reaktionen von Derivaten der (Diphenylmethylen-amino)-essigsäure mit Schwefelkohlenstoff und Phenylisothiocyanat sowie Kristall- und Molekülstruktur des 2-(Diphenylmethylen-amino)-2-(1,3-dithian-2-yliden)-essigsäuremethylesters / Reactions of the Derivatives of (Diphenylmethylene-amino) Acetic Acid with Carbon Disulfide and Phenyl Isothiocyanate and Crystal and Molecular Structure of Methyl 2-(Diphenylmethylene-amino)-2-(1,3-dithiane-2-ylidene) Acetate

Abstract

Derivatives of (diphenylmethylene-amino) acetic acid 1-3 react in the presence of bases (NaH, t-BuONa) or under phase transfer conditions with carbon disulfide to give the corresponding ketene dithioacetals 4-11 after alkylation. Phenyl isothiocyanate and dicyclohexyl carbodiimide give rise to ketene-S,N- and N,N-acetals. Methyl 2-(diphenylmethyleneamino)-2-(1,3-dithiane-2-ylidene) acetate (7) was characterized by an X-ray structure determination. The compound has a 2-aza-1,3-butadiene fragment containing two well localized double bonds. The C=N-C=C group is significantly non-planar, the relevant torsion angle amounts to -103.5(3)°.