A novel synthesis of dibenzo[b,f] [1,4]thiazepin-11(10H)one 5,5-dioxides

Treatment of thioxanthen-9-one 10,10-dioxides with sodium amide in liquid ammonia provided a novel one-step conversion to dibenzo[b,f][1,4]thiazepin-11(10H)one 5,5-dioxides. Some limitations and a possible mechanism for the reaction are discussed.     

Electron transfer from dibenzo[b,f]-1-azapentalene dianion: Attempted synthesis of dibenzo[b,f]-1-azapentalene

When dibenzo[b,f]-1-azapentalene dianion (3) was allowed to react with either iron (III) chloride or ethylene bromide, a one-electron transfer from3 took place readily to give the radical anion11. Further electron transfer from11 did not occur presumably due to the antiaromatic character of dibenzo[b,f]-1-azapentalene (1) that would have resulted. The radical anion11 underwent further transformation by hydrogen abstraction from the solvent to give 5,10-dihydroindeno[1,2-b]indole (2) and by dimerization to themeso and (R,S) isomers of 5,5,10,10-tetrahydro-10,10-biindeno[1,2-b]indole (4 a and4 b) respectively.

---

Elektronentransfer von Dibenzo[b,f]-1-azapentalen-Dianion: Ein Versuch zur Synthese von Dibenzo[b,f]-1-azapentalen

Zusammenfassung Die Reaktion von Dibenzo[b,f]-1-azapentalen-Dianion (3) mit Eisen (III) oder Ethylenbromid ergab einen Ein-Elektronentransfer zum Radikalanion11. Ein weiterer Elektronentransfer fand nicht statt, vermutlich wegen des antiaromatischen Charakters von Dibenzo[b,f]-1-azapentalen (1), das dabei entstehen müßte. Das Radikalanion11 ergab unter Wasserstoffentzug aus dem Lösungsmittel 5,10-Dihydroindeno[1,2-b]indol (2), das weiter zummeso- bzw. (R,S)-5,5,10,10-tetrahydro-10,10-biindeno[1,2-b]indol (4 a bzw.4 b) dimerisierte.

     

Determination of dibenzo [b,f]-1,4-oxazepine by extraction spectrophotometry

The spectrophotometric determination of the substance dibenzo [b,f]-1,4-oxazepine (CR) the form of an ionic associate with the anionactive dyes of the type of azo dyes, sulphonephthaleins and anthraquinones after extraction with chloroform was worked out. Conditional extraction constants K'(ex) were calculated and equilibrium ratios D and extraction yields E of ionic associates were determined. On the basis of detection limit L(Q), the dyes Alizarine Black S (0.7 microg/ml) and Orange II (0.8 microg/ml) were recommended for extractive spectrophotometric determination of the substance CR.     

Synthesis of dibenzo[b,f][1,4]oxazepin-11(10H)-ones from 2-nitrobenzoic acids

Base-catalyzed intramolecular nucleophilic substitution for the 2-nitro group in 2-hydroxyanilides of 2-nitrobenzoic acids gave dibenzo[b,f][1,4]oxazepin-11(10H)-ones. In particular, 3-nitrodibenzo[b, f][1,4]oxazepin-11(10H)-one was obtained from N-(2-hydroxyphenyl)-2,4-dinitrobenzamide. The nitro group in the product could also be replaced under the action of O- and S-nucleophiles. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 529–533, March, 2006.     

Determination of dibenzo[b,f]-1,4-oxazepine by diazotization cleavage of azomethine bond

A spectrophotometric determination of dibenzo[b,f]-1,4-oxazepine (CR) has been elaborated, which is based on a diazotation cleavage of azomethine bond followed by a coupling reaction. Twelve coupling agents have been used in the experiments and the following three agents have been recommended for the determination: N-(1-naphthyl)ethylenediamine dihydrochloride (L(Q) = 85 mg/ml), 7-hydroxy-4-methyl coumarin (L(Q) = 105 mg/ml) and 1-naphthol (L(Q) = 110 mg/ml). 2-[2-(hydroxy-l-naphthylazo) phenoxy]benzaldehyde has been identified by (1)H and (13)C NMR and elementary analysis as the product which results from the diazotization reaction followed by coupling of the CR substance with 2-naphthol. The azo-dye prepared by the described reactions shows azo-hydrazo tautomerism.     

11-Substituted polyfluorodibenz[b,f][1,4]oxazepines

Tetrafluorodibenz[b,f][1,4]oxazepin-11-(10H)-ones have been synthesized and converted to 11-chloro and 11-piperidino substituted polyfluorodibenz[b,f][1,4]oxazepines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 539–542, April, 1989.     

Novel polycyclic heterocycles. IX. Dibenz[b,f] [1,4]oxazocin-11 (12H)one, 6,11-dihydro-12H-dibenz[b,f] [1,4]oxazocine,and their derivatives

Dibenz[b,f][1,4]oxazocin-11 (12H)one, 14 , was synthesized by the dicyclohexylcarbodiimide induced cyclization of α-(o-aminophenoxy)-o-toluic acid ( 13 ). Reduction of 14 by lithium aluminum hydride gave 6,11-dihydro-12H-dibenz[b,f][1,4]oxazocine ( 16 ). Both 14 and 16 were converted to a series of 12-alkylated and -acylated derivatives. The pmr spectra of some of these compounds are discussed.     

A regiospecific synthesis of 1-methylamino-6-fluoro-7-(4-methylpiperazin-1-yl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid

An efficient and regiospecific synthesis of 1-methylamino-6-fluoro-7-(4-methylpiperizin-1-yl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid ( 3 ) via an intramolecular nucleophilic displacement cyclization reaction is reported.     

Dibenz [b,f]-1, 4-oxazepin-11 (10 H)-one und Dibenz [b,e]-1, 4-oxazepin-11 (5 H)-one. 12. Mitteilung über siebengliedrige Heterocyclen

The syntheses of dibenzo [b, f]-1, 4-oxazepin-11 (10 H)-ones (I) with electron-attracting substituents in position 2 by ring closure of the sodium salts of 2-halogeno-2′-hydroxy-benzanilides (II) are described. The reaction of II (R = SO₂·N(CH₃)₂) in N-methylpyrrolidone also led, by SMILES rearrangement, to the isomeric minor product dibenzo [b, e]-1, 4-oxazepin-11 (5 H)-one (III; R = SO₂·N(CH₃)₂), whose constitution was proven by synthesis from VI. In the case of II (R = SO₂·CH₃), the 5-methylsulfonyl-2-(2-hydroxyanilino)-benzoic acid (VI; R = SO₂·CH₃) was obtained directly after hydrolysis. The lactam I (R = NO₂) was rearranged to the corresponding acid VI by heating with dilute caustic soda.