22996-46-9

Upstream product

• 30897-86-0 2,5-dimethylphenylmagnesium bromide 
• 67-64-1 acetone 
• 917-64-6 methyl magnesium iodide 
• 2142-73-6 1-(2,5-dimethylphenyl)-1-ethanone 
• 4132-72-3 2,5-dimethylisopropylbenzene 
• 553-94-6 4-bromo-m-xylene 
• 106-42-3 para-xylene 

Downstream Products

• 106213-54-1 1,4-dimethyl-2-tert-pentyl-benzene 
• 4132-72-3 2,5-dimethylisopropylbenzene 

Relevant academic research and scientific papers

Indium(III) bromide-catalyzed chemioselective dimerization of vinylarenes

Indium(III) bromide catalyzes the dimerization of α-substituted vinylarenes. Chemioselectivity towards open chain or cyclic dimers depends on the nature of the substituent at the aryl group of the vinylarene.

Synthesis of diaryl methanes

The present Invention includes synthetic steps and intermediates involved in the following reaction scheme a of converting compounds of Formula (II) to the diarylmethanes of Formula (I): STR1 wherein: Y is oxygen or sulfur; A, B, C, D, and E are carbon or 1, 2 or 3 of A, B, C, D, and E are independently nitrogen, and the others are carbon; and wherein R1 through R10 are selected independently from the group consisting of: hydrogen, hydroxy, alkyl, C3 -C8 cycloalkyl, C3 -C8 cycloalkyl alkyl, alkenyl, hydroxy alkyl, alkoxy alkyl, perhalo-alkyl, amino, nitro, nitrile, halo, carboxyl, sulfonyl, acyl, formyl, carbamoyl, trifluoromethyl, aminomethyl, azido, amido, hydrazino, aryl, aryloxy, heteroaryl, or aryl or heteroaryl, mono, di, or tri substituted with one or more hydrogen, hydroxy, alkyl, C3 -C8 cycloalkyl, C3 -C8 cycloalkyl alkyl, alkenyl, hydroxy alkyl, alkoxy alkyl, perhaloalkyl, amino, nitro, nitrile, halo, carboxyl, sulfonyl, acyl, formyl, carbamoyl, trifluoromethyl, aminomethyl, azido, amido, hydrazino, aryl, aryloxy, or heteroaryl groups and; the pharmaceutically acceptable salts and solvates thereof.

Kinetics and Regioselectivity of the Autoxidation of o-Substituted Isopropyl Aromatics

The relative chain propagation constants and the regioselectivities of the oxidations of o-cymene and 2-isopropyl-1,4-dimethylbenzene were determined by competitive oxidations of the hydrocarbons with cumene.As expected, the reactivity of the tertiary C-H bond of the isopropyl group is considerably decreased by o-methyl groups.Also in α-isopropylnaphthalene a considerable decrease in the reactivity of the tertiary C-H bond takes place.The decrease of the chain propagation constants effects a decrease of the oxidabilities of o-substituted isopropyl aromatics.In the case of the methyl isopropyl benzenes the increase of the chain termination constants by primary peroxy radicals must also be taken into consideration.This results in a decrease of the oxidabilities which can be observed even in p-cymene (in comparison with cumene).

Preparation, Pyrolysis, and Photolysis of Three Sterically Crowded Alkenes, 3,3,3',3',5,5,5',5'-Octamethyl-3,3',5,5'-tetrahydro-4,4'-bi(4H-pyrazolylidene) 2,2,4,4-Tetramethyl-3-(3,3,5,5-tetramethyl-3,5-dihydro-4H-pyrazol-4-ylidene)-thietane 1,1-Dioxide and 2,2,2',2',4,4,4',4'-Octameth...

Photolysis and pyrolysis of the title compounds involve a stepwise elimination of nitrogen and/or sulphur dioxide and reactions which can be interpreted in terms of a series of trimethylenemethane (TMM) biradical intermediates.However, the photosensitised photolysis of the bi(pyrazolylidene) (11) give products indicative of an elimination of both nitrogens and the generation of a tetramethylene-ethane (TME) biradical intermediate.New synthesis of a number of highly sterically crowded alkenes including 2,2,4,4-tetramethyl-3-(3,3,5,5-tetramethyl-3,4-dihydro-4H-pyrazol-4-ylidene)thietane 1,1-dioxide (12) and 2,2,2',2',4,4,4',4'-octamethyl-3,3'-bithietanylidene 1,1,1',1'-tetraoxide (13), are described.Flash vacuum pyrolysis (f.v.p) of 3,3,3',3',5,5,5',5'-octamethyl-3,3'-5,5'-tetrahydro-4,4'-bi(4H-pyrazolylidene) (11) at 400 deg C gives 3,3,5,5-tetramethyl-4-(2,2,3,3-tetramethylcyclopropylidene)-3,5-dihydro-4H-pyrazole (21), at ca. 400 deg C 1-isopropylidene-2,2,4,4,5,5-hexamethylspiropentane (22), and at ca. 580 deg C a ca. 5:1 mixture of 4-isopropyl-3-isopropylidene-2,5-dimethylhexa-1,4-diene (23) and 2-(2,3-dimethylbut-1-en-3-yl)-1-isopropyl-3,3-dimethylcyclopropene (27).Above 700 deg C a complex mixture of aromatic products and low molecular weight hydrocarbons is produced which includes ethane, ethylene, propene, isobutane, and isobutene, p-xylene, o-cumene and probably m-cumene, and 2,5-dimethylisopropylbenzene.F.v.p. of the dihydropyrazole sulphone (12) gives initially 2,2,4,4-tetramethyl-3-(2,2,3,3,-tetramethylcyclopropylidene)thietane 1,1-dioxide (41) and at higher temperatures similar mixtures to those obtained from the bipyrazolylidene (11).Similar results were also obtained for the f.v.p. of the bis-sulphone (13).Photolysis of the bipyrazolylidene (11) gave initially the dihydropyrazole (21) and then a 48:52 mixture of the spiro compound (22) and 2,2,2',2',3,3,3',3'-octamethylbicyclopropylidene (42).Photolysis of the dihydropyrazole sulphone (12) gave 2,2,4,4-tetramethyl-3-(2,2,3,3-tetramethylcyclopropylidene)thietane 1,1-dioxide (41).Benzophenone-sensitised photolysis of the bipyrazolylidene (11) gave 1,2-di-isopropylidene-3,3,4,4-tetramethylcyclobutane (32).