Synthesis of Indeno[1,2-b]pyrazineN-Oxides by Reaction of Ninhydrin with 1,2-Bishydroxylamines

Autor: V. P. Vetchinov, Victor I. Mamatyuk, Aleksei Ya. Tikhonov, Dmitrii G. Mazhukin, Leonid B. Volodarsky, Natal'ya P. Evlampieva
Rok vydání: 1994
Předmět:
Zdroj: Liebigs Annalen der Chemie. 1994:983-987
ISSN: 1099-0690
0170-2041
Popis: The reaction of the ninhydrin (1) with 1,2-bishydroxylamines 2a–c affords dihydroindeno[1,2-b]pyrazine N,N′-dioxides 5a–c. The intermediates hexahydro- and tetrahydroindeno[1,2-b]pyrazines 3a and 4c, which have been isolated, are easily transformed into 5a, c. Heating of 5b, c or keeping of 5b on alumina gives indeno[1,2-b]pyrazine N-oxides 6b, c, N,N′-dioxide 7c and indeno[1,2-b]pyrazine 8. Treatment of 5b with a solution of hydrochloric acid in H2O/MeOH leads to 6b, whereas treatment of 5b with KOH furnishes mono-N-oxides 6b, 9 and dioxide 7b. Compound 8 is prepared by deoxygenation of 6b with TiCl3. The reduction of 6b with NaBH4 yields alcohol 10 and the reaction of 6b with NH2OH/AcOH gives a mixture of isomeric oximes (E)-11 and (Z)-11.
Databáze: OpenAIRE
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