Syntheses dans le domaine des composes polycycliques aromatiques—XXIII

Geerts-Evrard, F.; Martin, R. H.

doi:10.1016/s0040-4020(01)99116-1

Cited by 7 publications

(1 citation statement)

References 8 publications

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“…the lack of color in 5). The longest wavelength ultraviolet absorption band occurred at 394 nm, a value consistent with the presence of three linear aromatic rings.6 On the basis of the low yield and ultraviolet spectral data, we believe the product to be 2,4-diaminonaphtho[2,l-g]quinazoline (8) rather than 7. This is the first observed instance of a bisarylbiguanide cyclization proceeding via attack at the ß position of a naphthalene ring in preference to the a position.…”

mentioning

confidence: 79%

Quinazolines. XIII. Synthesis of polycyclic 2,4-diaminopyrimidines from aromatic amine hydrochlorides and sodium dicyanamide

Rosowsky¹,

Papathanasopoulos²

1974

J. Org. Chem.

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confidence: 79%

Quinazolines. XIII. Synthesis of polycyclic 2,4-diaminopyrimidines from aromatic amine hydrochlorides and sodium dicyanamide

Rosowsky¹,

Papathanasopoulos²

1974

J. Org. Chem.

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Synthesis and Characterization of Pyridine‐, Pyrazine‐, and Quinoxaline‐Derived [4]Helicenes and S‐Shaped Double [4]Helicenes

2018

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A systematic study of the synthesis and properties of 1‐aza‐, 4‐aza‐, and 1,4‐diaza[4]helicenes as well as the previously unknown S‐shaped double 1,4‐diaza[4]helicenes has been reported. The synthetic route to the aza‐ and diaza[4]helicenes involved an electrophile‐induced cyclization of 3(2)‐alkynyl‐2(3)‐(naphthalen‐1‐yl)azines (i.e., quinoxaline, pyrazine, pyridine), which were prepared in two steps from the commercially available ortho‐dihalo‐substituted azine. Trifluoroacetic acid (TFA) and ICl were used as electrophiles. The ICl‐promoted cyclization provided the 5‐iodo derivatives of the aza‐ and diaza[4]helicenes in yields of 47–71 %. The use of TFA as the electrophile afforded the helicenes along with isomeric products from an alternative cyclization and subsequent 1,2‐shift of the C–C bond (e.g., naphtho[2,1‐f]quinoxalines or naphtho[2,1‐a]phenazines, 87–89 % total yield, 1.5–1.8:1 ratio). The presence of an iodine substituent in the hetero[4]helicenes allowed for the introduction of an alkynyl group by using a Sonogashira reaction. The subsequent cycloizomerization upon treatment with TFA gave the S‐shaped double 1,4‐diaza[4]helicenes. The molecular structures and crystal packing of the synthesized hetero[4]helicenes relative to those of [4]carbohelicene have been discussed.

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Azachrysene preparation

Hearn

SWANSON

1981

Journal of Heterocyclic Chem

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Syntheses dans le domaine des composes polycycliques aromatiques—XXIII

Cited by 7 publications

References 8 publications

Quinazolines. XIII. Synthesis of polycyclic 2,4-diaminopyrimidines from aromatic amine hydrochlorides and sodium dicyanamide

Quinazolines. XIII. Synthesis of polycyclic 2,4-diaminopyrimidines from aromatic amine hydrochlorides and sodium dicyanamide

Synthesis and Characterization of Pyridine‐, Pyrazine‐, and Quinoxaline‐Derived [4]Helicenes and S‐Shaped Double [4]Helicenes

Azachrysene preparation

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