Diazotization Widman-Stoermer cinnoline synthesis

An important early method simulated the well-known Widman-Stoermer cinnoline synthesis. 3-Aminopyridine-2- or -4-alkenes such as (348) gave pyrido-[3,2-c]- or -[3,4-c]-pyridazines on diazotization and alkaline cyclization (66JCS(C)2053>. [Pg.243]

The first of many steps for the Widman-Stoermer cinnoline synthesis is diazotization. Of critical importance is the formation of dinitrogen trioxide (6) or a nitrosonium equivalent. The formation of 6 is followed by the... [Pg.493]

One of the widely used cinnoline syntheses is the transformation of diazotized o-aminoarylethylenes into this bicyclic system (Widman-Stoermer synthesis) (Scheme 69). [Pg.43]

WIDMAN-STOERMER SYNTHESIS. The synthesis of cinnolines by cyclization of diazotized o-aminoarylethylenes at room temperature. [Pg.1749]

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... [Pg.46]

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