von Richter (Cinnoline) Synthesis

V. von Richter, Ber. 16, 677 (1883).

Formation of cinnoline derivatives by diazotization of o-aminoarylpropiolic acids or o-aminoarylacetylenes followed by hydration and cyclization:

M. Busch, M. Klett, Ber. 25, 2847 (1892); N. J. Leonard, Chem. Rev. 37, 270 (1945); K. Schofield, J. C. E. Simpson, J. Chem. Soc. 1945, 512, K. Schofield, T. Swain, ibid. 1949, 2393; J. C. E. Simpson, Condensed Pyridazine and Pyrazine Rings (New York, 1953) p 16; G. R. Ramage, J. K. Landquist, Chemistry of Carbon Compounds IVB, 1217 (1959); G. T. Rogere et al., Tetrahedron Letters 9, 1028 (1968); A. C. Ellis et al., J. Chem. Soc. Chem. Comm. 1977, 152. Cf. Widman-Stoermer Synthesis.