Eingegangen am 5. Marz 19712-Halogen-bzw. 2.3-Dihalogen-Derivate 6 des Napthochinons-(1.4) ergeben rnit Diazomethan bzw. -8than instabile Addukte 7, die sich zu den Halogen-freien Pyrazolen 3 umwandeln; diese bilden sich auch bei der Dehydrierung entsprechender Addukte 2. 2-Methylsowie 2.3-Dialkyl-naphthochinone 9 liefern rnit den Diazoalkanen Al-Pyrazoline 10, deren Zersetzung in aprotischem Medium Cyclopropan-Derivate 12, in wa13rig-saurem Medium unter Alkyl-Wanderung homologe Naphthochinone 11 ergeben. Die rnit 10 isomeren A2-Pyrazoline (Typus 16) sind wesentlich stabiler.
Reactions of Quinones and a-Dicarbonyl Compounds with Diazoalkunes, XVIIII). Further Experiments with 1,4-Nuphthoquinone and its Halogeno-, Alkyl-and Phenyl DerivativesThe reaction of 2-halogeno-or 2,3-dihalogeno derivatives 6 of 1,4-naphthoquinone with diazomethane or -ethane leads to unstable adducts 7 which are converted to the halogen-free pyrazoles 3. These are formed also by dehydrogenation of the corresponding adducts 2. 2-Methyl-or 2,3-dialkylnaphthoquinones 9 and diazoalkanes give Al-pyrazolines 10. Their decomposition in an aprotic medium yields cyclopropane derivatives (12), while decomposition in aqueous acidic medium yields the homologous naphthoquinones 11. The A2-pyrazolines
Die Halogennaphthochinone (Ia) reagieren mit Diazoalkanen, wie z.B. (IIb), zu den Pyrazolinen (III), die unter Abspaltung von Halogenwasserstoff in das Pyrazol (IV) (68% Ausbeute) übergehen.
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