ISSN:
0009-2940
Keywords:
1,2,4-Triazines
;
[3 + 2] Cycloadditions
;
Singlet vinylcarbene
;
1,3-Dipole, three-carbon
;
Pyrrolo[1,2-d][1,2,4]triazines
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Thermally Induced Formal [3 + 2] Cycloadditions of 3,3-Dimethoxycyclopropene to Triazines, a Novel Synthesis of Pyrrolo[1,2-d][1,2,4]triazinesFormal [3 + 2] cycloaddition reactions of the π-delocalized singlet vinylcarbene/three-carbon 1,3-dipole 8, generated in a reversible, thermal ring opening of the cyclopropenone ketal 7, with a variety of substituted triazines lead to the novel pyrrolo[1,2-d][1,2,4]triazines 9 or 10. Compound 10c is protonated at N-2 by HClO4/HOAc to yield the salt 17c and alkylated at the same position by Meerwein reagent [O(CH3)3BF4] to give 18. 10c reacts smoothly with dimethyl acetylenedicarboxylate to provide the pyrido[2,1-f]pyrrolo[1,2-d][1,2,4]triazines 19 and 20. The pyrrolotriazine 14 in the presence of oxygen, daylight, and silica gel is readily oxidized to the triazine N-oxide 22. The crystal structures of 14, of the protonated species 17c and of the N-oxide 22 have been determined by X-ray diffraction methods.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19931261021
