Chemistry: electrical and wave energy – Processes and products – Processes of treating materials by wave energy
Reexamination Certificate
2001-03-22
2003-01-14
Wong, Edna (Department: 1741)
Chemistry: electrical and wave energy
Processes and products
Processes of treating materials by wave energy
Reexamination Certificate
active
06506285
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention relates to the synthesis of 5,5′-diformyl-2,2′-difuran and derivatives thereof, as well as to the derivatives themselves as new chemical compounds.
BACKGROUND OF THE INVENTION
Difunctional aromatic monomers have vast potential and uses in the polymer industry and are presently used in many applications. Present technology to produce difunctional monomers through two base nuclei from the single nucleus has been achieved utilising a metal halide intermediate. This technology has the disadvantage of requiring an initial halogenation step after which the halogenated nuclei are treated with a metal powder. High temperatures, long reaction time and laborious work-up procedures followed by low yields make this process uneconomical. Industrially the large quantities of metal powder required make this process extremely difficult to handle on a large scale, whilst the specific metal required must be chosen with care as to prevent conversion of the parent functional group to another functionality.
Presently industry is dominated by difunctional phenyl derivatives through either one or two base nuclei. No difunctional furan derivatives through two base nuclei are presently synthesised on an industrial scale, Considering 5,5′diformyl-2,2′difuran it has been found that this compound has been synthesised through an Ullmann condensation utilising 5-iodo-2-furaldehyde, palladium catalysed coupling of 2-furaldehyde, or via the photolytic dimerisation of 5-bromo-2-furfural. The reported syntheses of the target compound involve labrious preparation of the starting materials, numerous work-up steps, high cost and low yields,
It is an object of the present invention to prepare 5,5′-diformyl-2,2′-difuran and derivatives thereof in good yield and purity, and to avoid the use of high temperatures, solid metal powders and tedious work-up procedures.
REFERENCES:
patent: 4229202 (1980-10-01), Mullerheim et al.
Tymyanskii et al., “Photodimerization of Furfural Bromo Derivatives” , Zh. Org. Khim., vol. 24, No. 2, pp. 459-460. (month unavailable, 1988).*
Itahara, T., “Arylation of Aromatic Heterocycles with Arenes and Palladium(II) Acetate” , J. Org. Chem., vol. 50, pp. 5272-5275. (month unavailable, 1985).*
Markl et al., “Zur Molekuldynamik Isomerer Antiaromatischer [28 ]Tetraoxaporphyrinogene (6.0.6.0)-Isomer [26 ]Tetraoxaporphyrin (6.0.6.0) Dikationen” , Tetrahedron, vol. 52, No. 36, pp. 11763-11782. (month unavailable, 1996).
Burger Gregory James
Wills Alan Douglas
Illovo Sugar Limited
Wong Edna
Young & Thompson
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