Widman-Stoermer synthesis

One of the widely used cinnoline syntheses is the transformation of diazotized o-aminoarylethylenes into this bicyclic system (Widman-Stoermer synthesis) (Scheme 69). 

Widman-Stoermer synthesis, 3, 43 Wild-fire toxin, 7, 249 Willardiine,... 

WIDMAN-STOERMER SYNTHESIS. The synthesis of cinnolines by cyclization of diazotized o-aminoarylethylenes at room temperature. 

Widman-Stoermer synthesis, 3, 43 Wild-fire toxin, 7, 249 Willardiine, synthesis, 3, 146 Willgerodt reaction thiophene synthesis by, 4, 883 Williamson reaction oxetane synthesis by, 7, 390-391 Withasomnine occurrence, 5, 302 Wittig reaction crown ethers and, 7, 759 Wittig-Homer reactions crown ethers and, 7, 759 Wolff rearrangement oxirenes in, 7, 120, 126... 

In a cyclization reaction similar to the Widman- Stoermer synthesis of cinnolines (see Houben-Weyl, Vol. E9a, p 691), the diazotization of 2-(l-methylvinyl)pyridin-3-aminc in dilute hydrochloric acid gives 4-methylpyrido[3,2-c]pyridazine (3) in low yield.104... 

Cinnolines are prepared by an intramolecular cyclization of o-alkenyl or o-alkynyl aryldiazonium salts. For instance, (o-aminophenyl)alkynes 6 or alkyl(o-aminophenyl)ketones 8 (via the enol form) yield 4-hydroxycinnolines 7 (the v. Richter and Borsche syntheses, respectively), o-Aminostyrenes 10 afford 3,4-disubstituted cinnolines 11 (Widman-Stoermer synthesis) ... 

Among these methods, only the Widman-Stoermer synthesis is of preparative importance. 

This reaction is related to the Widman-Stoermer Synthesis and von Richter Cinnoline... 

Wharton Reaction Whiting Reaction Wichterle Reaction Widman-Stoermer Synthesis... 

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