Bromo Bromophenacyl Bromide

Bromophenacyl bromide has been prepared by the interaction of bromobenzene and bromoacetyl chloride in the presence of aluminum chloride2 and by the bromination of -bromo-acetophenone.1,3... 

Adding an alcoholic solution of phenacyl or 4-bromophenacyl bromide to[a solution of a carboxylic acid that has been neutralized with sodium carbonate gives an ester of a)-hydroxyaceto-phenone or of its 4-bromo derivative these esters crystallize well from ethanol and are useful for characterization of liquid acids. 

Biotin [97], its biogenetic precursor dethiobiotin and its sulphoxide and sulphone metabolites have been derivatized with p-bromophenacyl bromide or 4-bromo-methylmethoxycoumarin with dibenzo-18-crown-6 as the catalyst. The reaction products were separated on a C18 column. Both UV (254 nm) and fluorescence detection were used, with detection limits of 10 and 1 ng ml respectively. The derivatization has been applied to the analysis of valproic acid in serum and plasma [76, 77,98, 99]. The acid was extracted from biological matrices with organic solvents. Alric et al. [76] developed a procedure involving solvent demixing in which the extraction of valproic acid was achieved by saturation with potassium chloride following addition of acetonitrile and HCl to the plasma. The derivatization was performed in the acetonitrile phase after separation from the aqueous phase. The recovery was over 80%. The analysis was carried out on a Cig column with acetonitrile/water as the mobile phase. 

Benzylation of eucomin (3) with benzyl bromide and potassium carbonate in dimethyl formamide gives 5,7-di-O-benzyleucomin (43). If acetone is used as solvent additional C-benzylation at C-6 or C-8 takes place (25, 24). Again sodium acetate shows complete selectivity towards the activated hydroxyl at C-7 (64). Similarly 7-0(p-bromophenacyl)euco-mol (32) is isolated from the reaction of eucomol (10) with p-bromo-phenacyl bromide and sodium acetate or pivalate in acetone (74). 

Comparable phenacyl esters are synthesized with p-bromophenacyl bromide or p-nitrophenacyl bromide with a similar spectroscopic behavior (both p-Bondapak C18). Useful derivatization by tagging the COOH group can also be done with a-bromo-2 -acetonaphthone resulting in well-soluble and strongly UV-absorbing (254 nm) naphthanyl esters after a reaction time of only 10 min at ambient temperature (LiChrosorb Si-100). Furthermore, coumarin derivatives (substituted at position 7 for higher fluorescence quantum yields) are predestinated to... 

Bromo-1 -(4-bromophenyl)-ethanone p-Bromophenacyl bromide CjHgBrgO 99-73-0 277.941 nd (al) 111 iH20 sEt0H, eth, chi... 

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