US PATENT SUBCLASS 585 / 471
.~.~ Product is polycyclic, of increased side-chain length, or a specific position polyalkyl benzene isomer

Current as of: June, 1999
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585 /   HD   CHEMISTRY OF HYDROCARBON COMPOUNDS

400  DF  AROMATIC COMPOUND SYNTHESIS {15}
470  DF  .~ By alkyl or aryl transfer between molecules, e.g., disproportionation, etc. {3}
471.~.~ Product is polycyclic, of increased side-chain length, or a specific position polyalkyl benzene isomer {1}
472  DF  .~.~.~> Using Al or B halide catalyst {1}

DEFINITION

Classification: 585/471

Product is polycyclic, of increased side-chain length, or a specific position polyalkyl benzene isomer:

(under subclass 470) Subject matter wherein the product has more than one ring or in which the alkyl group removed from one hydrocarbon molecule is attached to a side-chain already on a ring of another molecule to give an aromatic product with a side-chain containing more carbon atoms than a feedstock side-chain, or in which the process is directed to maximize the production of a claimed isomer having alkyl groups in specific positions on a benzene ring, e.g., mesitylene, metaxylene, etc.

(1) Note. Only one ring of a polycyclic compound needs to be aromatic for placement in this subclass.

(2) Note. Where the process includes a step of removing or recovering a specific material substantially free from its isomers, it can be assumed that the process is directed to maximizing the production of the isomer removed or recovered.

(3) Note. Where the desired product has no aromatic position isomer, e.g., benzene, toluene, ethylbenzene, etc., the patent is not classified here.