S. Nan'ya, K. Katsuraya, E. Maekawa
Jul 1, 1987
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0
Influential Citations
10
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
The 1,3-dipolar cycloaddition of 3-phenylsydnone with p-toluquinone afforded 5-methyl- and 6-methyl-2-phenyl-2H-indazole-4,7-diones 3a and 3b. No regioselectivity was observed in this cycloaddition yielding an equimolar amount of the regioisomers. Reactions of 3a and 3b with bromine gave the corresponding mono-4a and 4b and dibromo derivatives 5a and 5b, respectively. The crystal structure of 6-bromo-5-methyl-2-phenyl-2H-indazole-4,7-dione (4a) has been determined by the single crystal X-ray method. The crystals are monoclinic, space group PI with two molecules in a unit cell of dimensions a = 8.029(1), b = 14.309(1), c = 5.895(1)A, β = 90.24(1)° and V = 621 A3. The structure has been solved by the direct method using 1827 reflections and refined by full-matrix least-squares calculations to R = 0.0739.