Bromo-/?-xylene

Tri-m-xylyl tellurium iodide, [(CH3)2C6H3]3TeI, from m-bromo-xylene, magnesium and tellurium tetrachloride in ether, subsequently treating the product with potassium iodide, crystallises from water as colourless needles, softening at 205° C. and melting at 208° to 209° C., soluble in chloroform or hot alcohol. The picrate separates as needles, sintering at 134° C., M.pt. 138° to 139° C. 

A. p-Methylbenzyltrimethylarmnonium bromide. In a 1-1. threenecked dask equipped with a stirrer, a reflux condenser provided with a Drierite drying tube, and a gas inlet tube about 1 cm. above the surface of the liquid are placed 600 ml. of dry ether and 100 g. (0.54 mole) of a-bromo- -xylene (Note 1). The flask is cooled in an ice-water bath with stirring. A dry, weighed trap... 

The ffl-bromo- -xylene was obtained from Eastman Organic Chemicals it melted at 35-36.5°. 

The procedure given was developed by Ghigi from an earlier preparation by Jacobsen. 4-Bromo-< -xylene has also been prepared from 3,4-dimethylamline by the Sandmeyer reaction. ... 

Perhydropyrido[l,2-c]pyrimidine was N-arylated with 6-bromo-l-(2-propyl)indole in the presence of DBU, NaO/-Bu, (/-Bu)3P, and Pd(OAc)2 in boiling xylene (01MIP6). 

Reaction of 7-bromo-4-(2,6-dichlorophenyl)-l,2-dihydro-3//-pyrido[l,2-c]pyrimidin-3-one (146) and PhSH in boiling xylene in the presence of Bu3SnOMe and (Ph3P)4Pd gave 7-(phenylthio) derivative in 52% yield (98MIP11, 00USP6147080). 

Caution This preparation should be conducted in a hood to avoid exposure to trimethyl-amine and to ct-bromo-p-xylene. 

I. 2-Methylcyclohexanol EK Decahydro-2-naphthol A a-Bromo-p-xylene A, EK, MCB Trimethylamine, anhydrous EK Phenothiazine EK, MCB Dibenzyl ketone EK, MCB Triethylamine MCB, EK Olefins A... 

Based on unrecovered starting material. b From 2-bromo-2, 4, 6 -trimethyl-4,6-dinitrodiphenyldiazene. c In refluxing xylene. 

A. Toluene diisocyates (TDI), xylene isocyanates, chloro-TDI, bromo-TDI, dichloro-TDI, and trichloro-TDI... 

Benzoic m-Toluic (Benzoic acid, 3-methyl-] p-Toluic [Benzoic acid, 4-methyl-J 3,5-Dimcthylbcnzoic [Benzoic acid, 3,5-dimcthyl-] p-Chlorobenzoic [Benzoic acid, 4-chloro-] p-Bromobenzoic [Benzoic acid, 4-bromo-J Phthalic [ 1,2-Bcnzcncdicarboxylic acid] Toluene [Benzene, methyl-] (78) m-Xylene [Benzene, 1,3-dimethyl-] (82) />-Xylene [Benzene, 1,4-dimethyl-] (74) Mesitylene [Benzene, 1,3,5-trimethyl-] (82) p-Chlorotolueno [Benzene, l-ehloro-4-methyl-] (94) p-Bromotolucnc [Benzene, l-bromo-4-methyl-] (94) o-Xylene [Benzene, 1,2-dimethyl-] (64)... 

Stock and Baker2 5 9 measured the relative rates of chlorination of a number of halogenated aromatics in acetic acid containing 20.8 M H20 and 1.2 M HC1 at 25 °C and the values of the second-order rate coefficients (103Ar2) are as follows p-xylene (11,450), benzene (4.98), fluorobenzene (3.68), chlorobenzene (0.489), bromobenzene (0.362), 2-chlorotoluene (3.43), 3-chlorotoluene (191), 4-chloro-toluene (2.47), 4-fluorotoluene (9.70), 4-bromotoluene (2.47). Increasing the concentration of the aromatic, however, caused, in some cases, a decrease in the rate coefficients thus an increase in the concentration of chlorobenzene from 0.1 M to 0.2 M caused a 20 % decrease in rate coefficient, whereas with 4-chloro-and 4-bromo-toluene, no such change was observed. 

An interesting, halogen-exchange reaction takes place when [Ni(Et2dtc)2] is refluxed in 1,2-dichloroethane with an excess of a,a -di-bromo-o-xylene and a-bromo-a -chloro-o-xylene. The products, a,a -... 

Bromo-m-xylene General Procedure for Bromination of Polymethylbenzene... 

The products mixture was filtered, and the spent and unused reagent were washed with carbon tetrachloride (30 ml). The solvent was evaporated from the combined filtrate under reduced pressure, and the residue was distilled under vacuum to give 3.6 g (86 %) of 4-bromo-m-xylene. Bp 89-91 °C/14 Torr (lit. 203°C (ref. 16)). 

In a method for the determination of copper, nickel, and vanadium in seawater, Shijo et al. [840] formed complexes with 2-(5-bromo-2 pyridylazo)-5-(N-propyl-N-sulfopropylamino) phenol and extracted these from the seawater with a xylene solution of capriquat. Following back-extraction into aqueous sodium perchlorate, the three metals were separated on a C is column by HPLC using a spectrophotometric detector. 

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