2H-l,3-Benzoxazin-4-ones

A solid-supported carbonate reagent was used to initiate the formation of 2H-l,4-benzoxazin-2-ones 303 from P-nitroacrylate 301 and 2-aminophenol 302 (Scheme 7.72) [154]. This hetero-Michael addition/intramolecular transesteri-fication/elimination of HN03/[l,3]-proton shift domino reaction proceeded in moderate to excellent yields. In another study, a series of various functionalized pyrrolo[l,2-r]pyrazines 305 were made synthetically available through the reaction of vinyl azides 304 and lH-2-pyrrolecarbaldehyde (Scheme 7.73). The deprotonated pyrrole initially reacts in a Michael manner with the vinyl azides, with nitrogen as... 

Ring contraction by decarbonylation Benzoxazoles from 2H-l,4-benzoxazin-2-ones... 

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