Electron-deficient heteroaromatic ammonioamidates. Part 27. Quinazolinioamidates. Part 14. N-Amination of some quinazoline derivatives and some reactions of the resulting quinazolinioamides

Abstract

Treatment of the quinazolines (4d) and (4e) bearing no substituents at position 4 with O- mesitylenesulphonylhydroxylamine leads to amination of N-3 and formation of the mesitylene- sulphonates of the corresponding (quinazolin-3-io)amides (5a) and (5b). Upon alkaline treatment these mesitylenesulphonates yield the free (quinazolin-3-io)amides (5a) and (5b) which exist predominantly in the form of the dimers (6a) and (6b), respectively. O-Mesitylenesulphonyl hydroxylamine aminates the 4-substituted quinazolines (4f)–(4h) at N-1, affording the mesitylenesulphonates (7b–d) of the corresponding (quinazolin-1-io)amides. The salts (7b) and (7c) undergo ring contraction to indazole derivatives of type (10) on alkaline treatment. All attempts to acylate the (quinazolin-3-io)amide (5a), its dimer, or its mesitylenesulphonate failed, whereas the mesitylenesulphonate of the (quinazolin- 1-io)amide (7b) could be both benzoylated and ethoxycarbonylated. Irradiation studies of the (quinazolin-3-io)amides (5a) and (5b), respectively, of their dimers (6a) and (6b), and of the N-(quinazolin-1-io)amidate (8c) are also reported.