ISSN:
1434-193X
Keywords:
Azides
;
Cleavage reactions
;
Cycloadditions
;
Nitrogen heterocycles
;
Polycycles
;
Ring expansion
;
Synthetic methods
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
---2-Alkyl-1-methylquinazolinium hexafluorophosphates 9 are deprotonated by sodium or potassium hydride to afford solutions of 2-alkylidenedihydroquinazolines 10, which were investigated by NMR spectroscopy. Trapping with methanesulfonyl azide (5a) of 10 in situ or subsequent treatment with trifluoromethanesulfonyl azide (5b) gives mixtures of colourless (15) and intensely yellow N-sulfonylimino-1,4-benzodiazepines 16 along with products due to cleavage of the exocyclic double bond of 10, viz. 11 and 13. The ethylidene compound 10b yields the bicyclic products 18 and 19, apparently by complex sequences of reactions that are triggered by removal of the acidic proton at C-2 of 16b and 16f. The structures of the products are based on spectroscopic evidence and X-ray diffraction analyses performed on 15b, 16d, 16e, and 19.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
