Studien über Hyrazoverbindungen

Rassow, Berthold

doi:10.1002/prac.19010640109

Cited by 9 publications

(7 citation statements)

References 2 publications

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“…Several reasonable reaction mechanisms can be written for the formation of the hydrazones (9) and (13). In view of previous work their formation via a sigmatropic [ 1,4]hydrogen migration in the putative azomethine imine intermediates (14) (Scheme 3) seemed very likely. It was of particular interest to us to find out if such intermediates were being generated because if so then apparently the [1,4]hydrogen shift in (lo), giving (9), is preferred to the expected 1,7-electrocyclisation reaction leading to (11).…”

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confidence: 76%

“…No adduct (15) was obtained and the reaction followed its usual path to give benzaldehyde dibenzylhydrazone (13c) in 93% yield. A second experiment was devised to find out whether the postulated [1,4]hydrogen shift converting (10) into (9) was, in fact, an intramolecular process. To this end partially deuteriated dibenzylhydrazine (16) was prepared and allowed to react with the aldehyde (7).…”

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confidence: 99%

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Reaction of aromatic aldehydes with 1,2-dibenzylhydrazine

Anderson¹,

Sharp²

1984

J. Chem. Soc., Perkin Trans. 1

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The reactions of 1,2-dibenzyIhydrazine with several aromatic aldehydes in refluxing toluene gave the benzaldehyde dibenzylhydrazones (9) and (1 3) in high yield. It is suggested from labelling studies and from the failure to trap an azomethine imine in the reaction between dibenzylhydratine and benzaldehyde that such intermediates are not involved in the formation of the hydrazones. These products may be formed directly via hydride transfer in the hydrazinocarbinol(l8) or the hydrazonium ion (1 9).Reactions between 1,Zdisubstituted hydrazines (1) and aldehydes (2) have been investigated by several groups, mainly with the objective of generating azomethine imines (4) (Scheme 1). The earliest reports on the use of 1,Zdiarylhydrazines were

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confidence: 76%

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confidence: 99%

Reaction of aromatic aldehydes with 1,2-dibenzylhydrazine

Anderson¹,

Sharp²

1984

J. Chem. Soc., Perkin Trans. 1

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“…Analogously to the above described procedure, a mixture of products 13-16 was obtained upon predissolution of diphenyl hydrazine 12 (1.84 g, 0.01 mol) in a solution of sodium butoxide 13 C NMR, δ: 21.2 (q, C(17), C(17´)); 62.2 (t, C(2), C(4), C(6), C(8)); 127.3 (d, C(12), C(16), C(12´), C(16´)); 129.4 (d, C(13), C(15), C(13´), C(15´)); 136.6 (s, C (14), C(14´)); 143.6 (s, C(11), C(11´)).…”

Section: Methodsmentioning

confidence: 99%

Cyclothiomethylation of aryl hydrazines with formaldehyde and hydrogen sulfide

et al. 2006

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Cyclothiomethylation of phenyl hydrazine with CH 2 O and H 2 S in a ratio of 1 : 3 : 2 in an acidic medium (HCl) afforded previously unknown 3 phenyl 1,3,4 thiadiazolidine (35% yield) and N phenyl(perhydro 1,3,5 dithiazin 5 yl)amine (35% yield). The analogous reaction in an alkaline medium (BuONa) produced N phenyl(perhydro 1,3 thiazetidin 3 yl)amine (22% yield). The reaction of 1,2 diphenyl hydrazine with CH 2 O and H 2 S in an alkaline medium gave 1,2,4,5 tetraphenylhexahydro 1,2,4,5 tetrazine and previously unknown 3,4 diphenyl 1,3,4 thiadiazolidine and 5,6 diphenyltetrahydro 1,3,5,6 dithiadiazepine in 39 and 22% yields, respectively. Cyclothiomethylation of benzyl hydrazine afforded previously unknown bis[(6 benzyl 4,2,6 thiadiazolidin 2 yl)methyl] sulfide (60% yield) and N ben zyl(perhydro 1,3,5 dithiazin 5 yl)amine (19% yield). The reaction of tosyl hydrazine produced 3 [(p tolyl)sulfonyl] 1,3,4 thiadiazolidine, N (perhydro 1,3,5 dithiazin 5 yl) p tolylsulfonamide, and 3,7 bis(p tolylsulfonylamino) 1,5 dithia 3,7 diazacyclooctane in 21, 38, and 41% yields, respectively.Earlier, 1 we have performed cyclothiomethylation of hydrazine with formaldehyde and hydrogen sulfide and prepared annelated 1,3,4 thiadiazolidines and 1,3,5 thia diazines. According to the available data, 2-4 1,3,4 thia diazole derivatives have found wide use as antibacterial and antiviral agents and as inhibitors of oxidation of cya nine dyes and metal complexing agents. 5 N Phenyl sub stituted nitrogen containing heterocycles, in which the N atoms are conjugated with chromophoric groups, are of particular interest as photosensitive and photocontrolled molecular devices. 6 The present study is a continuation of investigations on cyclothiomethylation of amines with CH 2 O and H 2 S. 7-9 Another aim was to develop efficient methods for the synthesis of aryl substituted thiadiazoles. The latter com pounds are of practical interest. We examined thio methylation of phenyl, 1,2 diphenyl, benzyl, and tosyl hydrazines with the H 2 S-CH 2 O system under neutral, acidic, and alkaline conditions. Results and DiscussionRecently, 10 we have found that the thiomethyla tion pathway of hydrazine with CH 2 O and H 2 S strongly depends on the starting component ratio, the heterocyclization temperature, and pH of the reaction mixture.In the present study, we examined cyclothio methylation of phenyl hydrazine hydrochloride (1•HCl) with CH 2 O and H 2 S in a ratio of 1 : 3 : 2 at pH 0.45-0.50 (method A). It was found that the reaction performed at 0 °C selectively produces 3 phenyl 1,3,4 thiadiazol idine (2), whereas N phenyl(perhydro 1,3,5 dithiazin 5 yl)amine (3) and 6 phenylperhydro[1,3,4]thiadiazi no [5,4 d] [1,3,5]dithiazine (4) are generated along with compound 2 at higher temperature (20-70 °C) (Scheme 1). At 70 °C, the amount of minor product 4 derived under these conditions from compound 3 is at most 8%.

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“…22 Ppm downfield from Me4Si. 6 Recorded at temperatures where passing nitrogen inversion is slow on the NMR time scale. cPreviously assigned from 'H NMR data.…”

Section: Methodsmentioning

confidence: 99%

“…This behavior is consistent with existence of each of [10][11][12][13] in a single set, which must be either set IV or set VII (Scheme III). 6 , 13H-1,4,8,1 l-Tetrahydrobis(py ridazino[ 1,2-a; 1 ',2'd]-s-tetrazine) (14). Th$ assignment of the NMR spectrum for this compound and the déuterated analogue 15 has previously been discussed in detail.2 The 13C NMR spectrum (Figure 9) offers striking confirmation of these conclusions.…”

Section: Methodsmentioning

confidence: 99%