Isatoic anhydride with hydrazides

As noted above, a convenient pathway to cinno-lines consists of intramolecular condensation of a diazonium group with a ketonic methyl group, or alternately with a double bond. The analogous reaction with an amide nitrogen leads to 1,2,3-benzotriazines, such as 198. Reaction of isatoic anhydride with N-aminomorpholine affords the hydrazide 196 then, treatment with nitrous acid yields initially the diazonium salt (197). Under the reaction conditions... 

Dihydro - 2,2,4 - trimethyl - 2H,6H -1,3,4-oxadiazino[2,3-6]quinazolines (654) were synthesized together with 2,3-dihydro-3-methyl-2-thioxo-6H-1,3,4-thiadiazolo[2,3-6]quinazolines by the reaction of isatoic anhydrides with l-[(2-hydroxy-2-methyl)propyl]hydrazine to give the corresponding anthranilic acid hydrazides (652), which were cyclized to the quinazoline intermediates 653 and then to 654 (79JHC1339). 

Isatoic anhydride can be used as a versatile synthon for the synthesis of a diverse set of molecules. The isatoic anhydride can be reacted with amines, amides, hydrazides, isothiocyanates, diketo substrates, aminoacids, amino-, thio or hydroxy anilines, as well as in a three-component reaction with aldehydes and amines to form a large set of diverse pharmacophores. 

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