Reaction pathways for the photochemical conversion of o-substituted benzylideneanilines to azoles

Grellmann, K. H.; Tauer, Erich

doi:10.1021/ja00791a003

Cited by 35 publications

(16 citation statements)

References 2 publications

(3 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Their postulation is based on the assumption that the tetrahydrobenzoxazinobenzoxazine 5 is indeed the investigated compound. We believe that this assumption is well justified because in the crystalline state the assignment of structure 5 to the condensation product is unambiguous and the spectral properties of solutions of 5 show that it does not rearrange into 4 when it is dissolved.…”

Section: : R = Chz-cchiimentioning

confidence: 95%

See 1 more Smart Citation

The condensation product of 2‐aminophenol and glyoxal. Structure and photochemistry

et al. 1986

View full text Add to dashboard Cite

It has been shown by X-ray analysis that the condensation product of 2-aminophenol and glyoxal is 5a,6,11a,12-tetrahydro[1,4]benzoxazino[3,2-h][1,4]benzoxazine (5) and not, as generally assumed'), 2,2'-bibenzoxazoline (4). The structure of 5 is preserved if it is dissolved in neutral solvents. Thermal oxidation of 5 leads preferentially to the formation of bibenzoxazole 7 and only with small yields to benzoxazinobenzoxazine 8. The photooxidation reaction of 5 is wavelength dependent. Long wavelength excitation yields exclusively 7, short wavelength excitation yields also 7, but in addition 8. The photooxidation 5+7 requires two photons: The first product is the metastable dihydrobibenzoxazole 10 which is converted by a second photon into 7. The photooxidation 5 -4 3 is presumably a one-photon process. Struktur und Photochemie eines Kondensationsproduktes aus ZAminophenol und GlyoxalMit Hilfe der Rontgen-Strukturanalyse konnte gezeigt werden, daB bei der Kondensation Bei kurzwelliger Anregung entsteht ebenfalls 7, daneben jedoch auch 8. Zur Photooxidation 5+7 sind zwei Photonen erforderlich. Zunachst bildet sich das metastabile Dihydrobibenzoxazol 10, aus dem nach der Absorption eines zweiten Photons 7 entsteht. Die Photooxidation 5-8 ist wahrscheinlich ein Ein-Quanten-ProzeB. The Structure of the Condensation ProductFor the condensation product (CP) of 2-aminophenol (1) and glyoxal (2) the structures 3 to 6 are conceivable (Scheme 1). Since CP forms chelates with a number of divalent cations (e.g. Cu2@, Mg2@, Ca2@), Bayer') first assumed that the Schiff base 3 is the chelating reagent. CP is commercially available (Fluka)

show abstract

Section: : R = Chz-cchiimentioning

confidence: 95%

“…It has been shown by X-ray analysis that the condensation product of 2-aminophenol and glyoxal is 5a,6,11a,12-tetrahydro [1,4] (5) and not, as generally assumed'), 2,2'-bibenzoxazoline (4). The structure of 5 is preserved if it is dissolved in neutral solvents.…”

mentioning

confidence: 94%

The condensation product of 2‐aminophenol and glyoxal. Structure and photochemistry

et al. 1986

View full text Add to dashboard Cite

show abstract

“…The overall geometry about the central rhenium atom is best described as skewtrapezoidal-bipyramidal [24,25] [26]. One of the 2-mercaptophenylaminomethyl groups was stabilized by coordination to the rhenium ion center, while the other uncoordinated 2-mercaptophenylaminomethyl group may first condense to the benzothiazoline group, and subsequently oxidize to the benzothiazolato group with the evolution of molecular hydrogen [27]. The Re(1)−N(2) distance of 2.047(7)Å is about 0.1Å shorter than Re(1)−N(3), a characteristic observation for the deprotonation of a secondary amine upon coordination with the rhenium core.…”

Section: X-ray Structure Determinationmentioning

confidence: 99%

An unexpected ‘4+2’ [N3S]/[NS] rhenium(IV) complex formed upon cleavage of a Re(V) imido bond

Chen

Femia

Babich³

et al. 2000

Inorganica Chimica Acta

View full text Add to dashboard Cite

show abstract

“…Illumination of 3-phenyl-2H-l,4-benzoxazin-2-one (6) leads to the formation of 2-phenylbenzoxazole (2) and CO. From the excited singlet state of 6 other transients are formed than from its triplet state. In protic solvents in addition to 2, the Schiff base N-benzylidene-2-aminophenol (7) is formed under ring opening from the triplet state of 6.…”

Section: Photochemical Reactions Of 3-phenyl-2h-14benzoxazin-2-one Amentioning

confidence: 99%

“…Es lag deshalb nahe, ahnliche Schiffsche Basen zu untersuchen, die am a-C-Atom bereits Sauerstoff tragen. Kondensiert man zu diesem Zweck 2-Aminophenol(3) mit Phenylglyoxylsaure (4), dann erhalt man als stabiles Endprodukt 3-Phenyl-2H-1 ,Cbenzoxazin-2-on (6 …”

Section: Photochemical Reactions Of 3-phenyl-2h-14benzoxazin-2-one Aunclassified

Photochemische Reaktionen von 3‐Phenyl‐2 H ‐1,4‐benzoxazin‐2‐on und von verwandten Verbindungen im Singulett‐ und Triplett‐Zustand

Tauer

Grellmann

1986

Chem. Ber.

View full text Add to dashboard Cite

Bei der Belichtung von 3-Phenyl-2H-1,4-benzoxazin-2-on (6) in Losung entsteht unter COAbspaltung 2-Phenylbenzoxazol (2). Die Reaktion verlauft im elektronisch angeregten Singulettzustand iiber andere Zwischenstufen als im angeregten Triplettzustand von 6. In protischen Losungsmitteln entsteht unter RingBffnung iiber den Triplettzustand von 6 noch die Schiffsche Base N-Benzyliden-2-aminophenol(7). Einige bei der Photolyse von 6 entstehende Zwischenverbindungen wurden in kinetischen Experimenten nachgewiesen und charakterisiert. Es wird kurz daruber berichtet, daB die Photolyse des analogen Phenylbenzothiazinons ahnlich verlauft wie die Photolyse von 6, wahrend entsprechende Phenylchinoxalinone anders reagieren. Photochemical Reactions of 3-Phenyl-2H-1,4benzoxazin-2-one and of Related Compounds in the Singlet and Triplet StateIllumination of 3-phenyl-2H-l,4-benzoxazin-2-one (6) leads to the formation of 2-phenylbenzoxazole (2) and CO. From the excited singlet state of 6 other transients are formed than from its triplet state. In protic solvents in addition to 2, the Schiff base N-benzylidene-2-aminophenol (7) is formed under ring opening from the triplet state of 6. In kinetic experiments some transients emerging during the photolysis of 6 were observed and characterized. We show qualitatively that the sulfur-containing analogue to 6, phenylbenzothiazinone, reacts similar to 6 and that corresponding phenylquinoxalinones have different properties.Die vorliegende Arbeit schliel3t an friihere Untersuchungen aromatischer Schflscher Basen an, die folgendes gezeigt haben? Belichtet man Losungen der Schiffschen Basen 1 in Methylcyclohexan (MCH), so entsteht in Gegenwart uon Sauerstoff2-Phenylbenzoxazol(2) und Aldehyd (R' = H) bzw. Keton [GI. (l)].Die Photoreaktion (1) verlauft uber radikalische Zwischenstufen und beginnt mit einem Angriff des Sauerstoffs am aliphatischen a-C-Atom der CarbimidoylgruppeIn entgaster Losung bildet sich 2 nicht. Es lag deshalb nahe, ahnliche Schiffsche Basen zu untersuchen, die am a-C-Atom bereits Sauerstoff tragen. Kondensiert man zu diesem Zweck 2-Aminophenol(3) mit Phenylglyoxylsaure (4), dann erhalt man als stabiles Endprodukt 3-Phenyl-2H-1 ,Cbenzoxazin-2-on (6). Die Schiffsche

show abstract

Reaction pathways for the photochemical conversion of o-substituted benzylideneanilines to azoles

Cited by 35 publications

References 2 publications

The condensation product of 2‐aminophenol and glyoxal. Structure and photochemistry

The condensation product of 2‐aminophenol and glyoxal. Structure and photochemistry

An unexpected ‘4+2’ [N3S]/[NS] rhenium(IV) complex formed upon cleavage of a Re(V) imido bond

Photochemische Reaktionen von 3‐Phenyl‐2 H ‐1,4‐benzoxazin‐2‐on und von verwandten Verbindungen im Singulett‐ und Triplett‐Zustand

Contact Info

Product

Resources

About