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Reaktionsprodukte aus 3-Dimethylamino-2,2-dimethyl-2H-azirin und Phthalohydrazid bzw. Maleohydrazid


Link, Helmut; Bernauer, Karl; Chaloupka, Stanislav; Heimgartner, Heinz; Schmid, Hans (1978). Reaktionsprodukte aus 3-Dimethylamino-2,2-dimethyl-2H-azirin und Phthalohydrazid bzw. Maleohydrazid. Helvetica Chimica Acta, 61(6):2116-2129.

Abstract

Reaction Products from 3-Dimethylamino-2,2-dimethyl-2H-azirine and Phthalohydrazide or Maleohydrazide
3-Dimethylamino-2,2-dimethyl-2H-azirine (1) reacts in dimethylformamide at room temperature with the six-membered cyclic hydrazides 2,3-dihydrophthalazin-1,4-dione (2) and 1,2-dihydropyridazin-3,6-dione (15) to give the zwitterionic compounds 3 and 16, respectively (Schemes 1 and 7). The mechanism of these reactions is outlined in Scheme 1 for compound 3 (cf: also Scheme 8). The first steps are thought to be similar to the known reactions of 1 with the NH-acidic compounds saccharin and phthalimide (cf. [1]). Instead of ring expansion to the nine-membered heterocycle i (X = CONH, Scheme 8), a proton transfer followed by the loss of water gives 3 (Scheme 1).
The structure of the zwitterionic compounds 3 and 16 is deduced from spectral data and the reactions of these compounds (see Schemes 2, 3, 4, 6 and 7). Methylation of 3 yields the iodide 4, which is hydrolysed easily to the 2-imidazolin-5-one derivative 5 (Scheme 2). Hydrolysis of 3 under basic conditions leads to the amide 6, which undergoes cyclization to 7 at 220-230° (Scheme 3). The analogous cyclization has been realized under acidic conditions in the case of 17 (Scheme 7).
Catalytic reduction of 3 yields the tertiary amine 14 (Scheme 6), whereas the reduction with sodium borohydride leads to a mixture of 14 and the 2-imidazoline derivative 13. The alcohol 11, corresponding to the amine 14, is obtained by sodium borohydride reduction of the 2-imidazolin-5-one 7 or of the amide 6 (Scheme 3). This remarkably easy reaction of 7 shows the unusual electrophilicity of the lactam-carbonyl group in this compound. The reduction of 6 to 11 is understandable only by neighbouring group participation of N(2') in the dihydrophthalazine residue.

Abstract

Reaction Products from 3-Dimethylamino-2,2-dimethyl-2H-azirine and Phthalohydrazide or Maleohydrazide
3-Dimethylamino-2,2-dimethyl-2H-azirine (1) reacts in dimethylformamide at room temperature with the six-membered cyclic hydrazides 2,3-dihydrophthalazin-1,4-dione (2) and 1,2-dihydropyridazin-3,6-dione (15) to give the zwitterionic compounds 3 and 16, respectively (Schemes 1 and 7). The mechanism of these reactions is outlined in Scheme 1 for compound 3 (cf: also Scheme 8). The first steps are thought to be similar to the known reactions of 1 with the NH-acidic compounds saccharin and phthalimide (cf. [1]). Instead of ring expansion to the nine-membered heterocycle i (X = CONH, Scheme 8), a proton transfer followed by the loss of water gives 3 (Scheme 1).
The structure of the zwitterionic compounds 3 and 16 is deduced from spectral data and the reactions of these compounds (see Schemes 2, 3, 4, 6 and 7). Methylation of 3 yields the iodide 4, which is hydrolysed easily to the 2-imidazolin-5-one derivative 5 (Scheme 2). Hydrolysis of 3 under basic conditions leads to the amide 6, which undergoes cyclization to 7 at 220-230° (Scheme 3). The analogous cyclization has been realized under acidic conditions in the case of 17 (Scheme 7).
Catalytic reduction of 3 yields the tertiary amine 14 (Scheme 6), whereas the reduction with sodium borohydride leads to a mixture of 14 and the 2-imidazoline derivative 13. The alcohol 11, corresponding to the amine 14, is obtained by sodium borohydride reduction of the 2-imidazolin-5-one 7 or of the amide 6 (Scheme 3). This remarkably easy reaction of 7 shows the unusual electrophilicity of the lactam-carbonyl group in this compound. The reduction of 6 to 11 is understandable only by neighbouring group participation of N(2') in the dihydrophthalazine residue.

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Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Department of Chemistry
Dewey Decimal Classification:540 Chemistry
Language:German
Date:1978
Deposited On:24 Aug 2014 08:30
Last Modified:05 Apr 2016 18:20
Publisher:Wiley-Blackwell Publishing, Inc.
ISSN:0018-019X
Funders:Schweizerischer Nationalfonds zur Förderung der wissenschaftlichen Forschung

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