Bromophenacyl bromide

In a 500-cc. flask are placed 50 g. (0.25 mole) of / -bromoaceto-phenone (Org. Syn. 5, 17) and 100 cc. of glacial acetic acid. To the resulting solution is very slowly added 40 g. (0.25 mole) of bromine, keeping the temperature below 20°. The mixture is vigorously shaken by hand during the addition. / -Bromo-phenacyl bromide begins to separate as needles when about one-half of the bromine has been added. The addition requires about thirty minutes. 

When all the bromine has been added, the flask is cooled in ice-water and the product filtered with suction. The crude crystals are washed with 50 per cent ethyl alcohol until colorless (about 100 cc. is required). The material so obtained, when air-dried, melts at 106-108° and weighs 55-60 g. It is recrystallized from 400 cc. of 95 per cent ethyl alcohol, from which it separates as colorless needles melting at 108-109°. The yield (Note 1) is 48-50 g. (69-72 per cent of the theoretical amount). 

A further quantity of less pure material may be obtained from the mother liquor from the recrystallization. If the acetic acid mother liquor is treated with water until turbid and then chilled, 4-5 g. of yellow crystals may be obtained. The material recovered from both liquors (6-8 g. in all) cannot be obtained 

Judefind and Reid 1 have shown that many acids may be identified by conversion into their -bromophcnacyl esters by the action of J -bromophenacyl bromide on the sodium salts. 

J)-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 

This substance is conveniently obtained by treating p-bromoacetophenone (Section IV, 138) with the calculated quantity of bromine dissolved in glacial acetic acid  

Place a solution of 50 g. of p bromoacetophenone (Section IV,138) in 100 ml. of glacial acetic acid in a 500 ml. flask. Add very slowly (about 30 minutes) from a dropping funnel 40 g. (12-5 ml.) of bromine shake the mixture vigorously during the addition and keep the temperature below 20°. p-Bromophenacyl bromide commences to separate as needles after about half of the bromine has been introduced. When the addition is complete, cool the mixture in ice water, filter the crude product at the pump, and wash it with 50 per cent, alcohol imtil colourless (about 100 ml. are required). RecrystaUise from rectified (or methylated) spirit (ca. 400 ml.). The yield of pure p-bromophenac bromide (colourless needles, m.p. 109°) is 50 g. 

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Sorbic add, benzoic acid Apply sample solution in the form of a band, followed by 0.5% 4-bromophenacyl bromide in A, A -dimethylformamide. Heat to 80 °C for 45 min, dry and chromatograph. [78]... 

Ueno and Okawara (184) were the first to explicitly formulate a conjugated thiocarbonyl ylide as an intermediate in the reaction of l,3-dithiolane-2-thione with 4-bromophenacyl bromide. The initially formed thiocarbonyl ylide undergoes deprotonation with sodium hydride to give 2-(4-bromophenyl)-l-oxa-4,6,9-trithias-piro[4.4]non-2-ene. 1,3-Diacylated thiocarbonyl ylides of type 149 (Scheme 5.45) have also been proposed as intermediates in the reaction of 1,3-diphenylpropane-1,3-dione with thionyl chloride. This reaction leads to 2,2,4-tribenzoyl-5-phenyl-... 

Keywords 4-bromophenacyl bromide, azole derivative, /V-alkylation, microwave irradiation, azalieterocycle... 

The equimolar mixture (3 mmol) of 4-bromophenacyl bromide and the corresponding azole was placed into a Pyrex-glass open vessel and irradiated in a domestic microwave oven. When the irradiation was stopped, the final temperature was measured by introducing a glass thermometer into the reaction mixture and homogenizing it, in order to obtain a temperature value representative of the whole mass. The reaction mixture was washed with cold water and the products were filtered off and conveniently dried, then recrystallized from absolute ethanol. 

C. 5-(4-Bramobenzoyl)-2-morpholino-3-phenylthiophene. A mixture of 3.18 g (0.01 mol) of 3-morpholino-2-phenylthioacrylic acid morpholide, 2.8 g (0.01 mol) of 4-bromophenacyl bromide, and 50 mL of methanol is heated to boiling. After the addition of a solution of 1.01 g (0.01 mol) of triethylamine in 10 mL of methanol to the mixture, the reaction is allowed to heat at reflux for 10 min. The reaction mixture is then cooled to 0°C in a refrigerator for 1 hr. The yellow crystalline product is collected by filtration and washed with 20 mL of cold methanol. After drying in the open air for 18 hr, 4.15 g (97%) of analytically pure product is obtained, mp 176-177°C (mp2 175°C). Although not necessary, the material can be recrystallized from acetonitrile. 

Bromophenacyl bromide, / -C6H4Br-COCH2Br, m.p. 108-109°, separates in crystalline form when 1 mole of Br2 is added to 4-bromoacetophenone dissolved in twice its amount of glacial acetic acid at 20°.697 4,a,a-Tribromoacetophenone, p-C6H4Br-COCHBr2, is also readily formed on use of 2 moles of bromine.698... 

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. 

Another synthon to 4-oxocarboxylic acids has been recently described and utilized for the synthesis of pyridazinones of potential antihypertensive activity. Thus, arylmethylene Meldrum acid derivatives 97 (prepared by reacting Meldrum acid 96 with aldehydes and subsequent reduction of the formed arylidene derivative using triethylammonium formate, TEAF) could be alkylated with 4-bromophenacyl bromide 98 to yield 99 that then reacted with hydrazine hydrate to yield 100 (2004SC783 Scheme 17). 

Sample preparation Dilute urine 10-fold with water. Mix 50 ixL plasma or diluted urine with 50 p,L 100 mM potassium dihydrogen phosphate, vortex, add 900 xL reagent, vortex, heat at 80° for 1 h, cool to room temperature, vortex, centrifuge at 1000 g, inject a 15 p.L aliquot of the supernatant. (Prepare the reagent by dissolving 66 mg 18-crown-6 and 1.39 g 4-bromophenacyl bromide in 100 mL MeCN.)... 

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