264. Studies in tar hydrocarbons. Part I. Reduction products of pyrene

Coulson, E. A.

doi:10.1039/jr9370001298

Cited by 17 publications

(7 citation statements)

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“…dehydrogenation with Pd/C 47,60,66 and treatment with halogens 50,52,57,67,68 have also been used. There are also examples employing selenium, 44 sulphur 68 and o-chloranil. 48,69 The utility of THPy as a source of 2-substituted pyrenes was first described by R. Bolton in 1964, who prepared 2-nitro-15, 2-acetyl-21 and 2-benzoylpyrene 22 for the first time in moderate to good yields after two steps by using this strategy (Scheme 6).…”

Section: The Tetrahydropyrene (Thpy) Methodsmentioning

confidence: 99%

“…10% yield) from hydrogenation of pyrene under vigorous conditions (100 bar, 400 °C) using a molybdenum-sulphur-carbon catalyst. 44 However, later studies indicated that hydrogenation can be limited to the K-region by tuning conditions of the reaction. 45,46 Currently there are several methods reported for the preparative synthesis of THPy using H 2 /Pd/C in EtOAc (Table 1).…”

Section: The Tetrahydropyrene (Thpy) Methodsmentioning

confidence: 99%

“…When using Na in 1-pentanol or isoamyl alcohol the main product of the reduction is HHPy 13, which can be isolated in very pure form by a simple crystallisation from EtOH. 44,55,75 The reactivity of 13 towards E A S reactions is straightforward, as only one position is available for the first substitution. 26 This allows the preparation of pyrene derivatives substituted on their K-region if a subsequent re-aromatisation step with o-chloranil or DDQ is applied (Scheme 16).…”

Section: The Hexahydropyrene (Hhpy) Methodsmentioning

confidence: 99%

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Synthesis of substituted pyrenes by indirect methods

2014

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The pyrene nucleus is a valuable component for materials, supramolecular and biological chemistry, due to its photophysical/electronic properties and extended rigid structure. However, its exploitation is hindered by the limited range of methods and outcomes for the direct substitution of pyrene itself. In response to this problem, a variety of indirect methods have been developed for preparing pyrenes with less usual substitution patterns. Herein we review these approaches, covering methods which involve reduced pyrenes, transannular ring closures and cyclisations of biphenyl intermediates. We also showcase the diverse range of substituted pyrenes which have been reported in the literature, and can serve as building blocks for new molecular architectures.

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Section: The Tetrahydropyrene (Thpy) Methodsmentioning

confidence: 99%

Section: The Tetrahydropyrene (Thpy) Methodsmentioning

confidence: 99%

Section: The Hexahydropyrene (Hhpy) Methodsmentioning

confidence: 99%

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Synthesis of substituted pyrenes by indirect methods

2014

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“…The monomers of 2-bromoisophthalic acid, dimethyl-2-bromoisophthalate, and tetramethylbiphenyl-2,2 ',6,6 '-tetracarboxylate were synthesized according to Coulson,21 whereas phenylterephthalic acid was synthesized according to the procedures of Preston et a1.22 and Weisburger and W e i~b u r g e r .~~…”

Section: Monomer Synthesismentioning

confidence: 99%

Rigid rod polyamides based on 2,2′,6,6′‐tetrasubstituted biphenyls: Synthesis, characterization, and structures

Griffin

Windle

1994

J of Applied Polymer Sci

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SYNOPSISPolyamides based on 4,4'-diamino-2,2',6,6'-tetrasubstituted biphenyls and phenylterephthalic acid have been synthesized, and the structures and properties of this series of polymer have been studied. It is shown that the polymers have a n amorphous structure although some degree of short-range order is present. This class of polymer, while consisting of comparatively stiff rodlike molecules, demonstrates high solubility and low glass transition temperatures. The behavior is due to the combination of the noncoplanar conformation of the twisted biphenyl and the fact that they have bulky side groups in the 2,2'-and 6,6'positions that weaken the interchain interactions (like hydrogen bonding and van der Waals forces) and frustrate parallel packing of the polymer chains. 0

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“…The oxidation took place more readily than did the oxidation of 4-chloro-l,3-dimethylbenzene, although the yields were nearly the same. No description of 2-chloroisophthalic acid could be found in the literature, although 2-bromoisophthalic acid (12) and 2-iodoisophthalic acid (13) have been reported. The condensation with p-toluidine to form 2-(p-rnethylphenylamino)-isophthalic acid (XXII) required less rigorous conditions than the condensation involving 4-chloroisophthalic acid.…”

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confidence: 99%