A Simple Approach for the Synthesis of 7,8-Diaza[5]helicene

Abstract

An oxidative route for the formation of 7,8-diaza[5]helicene and the corresponding N-oxides in high yields was developed. A mechanism of formation and possible interconversion of these products is put forward. Reduction of the N-oxides provided the title compound in quantitative yield.

diaza[5]helicenes - oxidation - amines - N-oxides - heterocycles

References

<A NAME="RZ23907SS-1A">1a</A> Meisenheimer J. Witte K. Ber. Dtsch. Chem. Ges.  1903,  36:  4153 

<A NAME="RZ23907SS-1B">1b</A> Cumming WM. Ferrier GS. J. Chem. Soc.  1924,  1108 

<A NAME="RZ23907SS-2">2</A> Bellaart AC. Tetrahedron  1965,  21:  3285 

<A NAME="RZ23907SS-3">3</A> Braithwaite PSW. Holt PF. J. Chem. Soc.  1959,  3025 

<A NAME="RZ23907SS-4">4</A> Bjørsvik H.-R. Gonzales RR. Liguori L. J. Org. Chem.  2004,  69:  7720 

<A NAME="RZ23907SS-5">5</A> Holt PF. Went CW. J. Chem. Soc.  1963,  4099 

<A NAME="RZ23907SS-6">6</A> Sakaue S. Tsubakino T. Nishiyama Y. Ishii Y. J. Org. Chem.  1993,  58:  3633 

<A NAME="RZ23907SS-7">7</A> Greenspan FP. Ind. Eng. Chem.  1947,  39:  847 

<A NAME="RZ23907SS-8">8</A> Corbett JF. Holt PF. J. Chem. Soc.  1961,  3695 

<A NAME="RZ23907SS-9">9</A> For example, see: Bamberger E. Rising A. Ber. Dtsch. Chem. Ges.  1900,  33:  3623 

<A NAME="RZ23907SS-10">10</A> Calcasi M. Tordo P. Gronchi G. J. Phys. Chem.  1986,  90:  1403 

<A NAME="RZ23907SS-11">11</A> Houben-Weyl Methoden der organischen Chemie   Vol. X/3:  Müller E. Georg Thieme; Stuttgart: 1965. and references cited therein