A-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... 

More recently, 4-methylbenzyl 25 and 4-methoxybenzyl (Mob) protection17 was proposed for the selenol group. The 4-methylbenzyl group is introduced by reacting selenocysteine with a-bromo-p-xylene following essentially the procedure for the preparation of the related cysteine derivative. 25 This type of protection is applied in combination with the Boc/Bzl strategy and its removal is achieved by HF treatment in the presence of 15% anisole and 2.5% ethyl methyl sulfide at 0°C in one hour. Unfortunately, experimental details were not reported by Oikawa et al. 25 ... 

Caution This -preparation should he conducted in a hood to avoid exposure to trimethylamine and to a-bromo-p-xylene. 

A. p-Methylbenzyltrimethylammonium bromide. In a 1-1. threenecked flask 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-p-xylene (Note 1). The flask is cooled in an ice-water bath with stirring. A dry, weighed trap... 

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