2-bromobenzaldehyde

Equip a 1 litre three-necked flask writh a reflux condenser, a mechanical stirrer, and a cork carrying a dropping funnel and a thermometer which reaches nearly to the bottom of the flask connect the upper end of the condenser to an absorption trap (Fig. II, 8, 1). Place 100 g. of p-bromo-toluene (Section IV,62) in the flask and immerse the latter in an oil bath (colourless oil in a large beaker). Heat the bath until the temperature of the stirred p-broniotoluene reaches 105°. Illuminate the liquid with 

Equip a I litre three-necked flask with a mechanical stirrer and a thermometer, and immerse the flask in a bath of ice and salt. Place 306 g. (283 ml.) of acetic anhydride, 300 g. (285 ml.) of glacial acetic acid and 25 g. of p-nitrotoluene in the flask, and add slowly, with stirring, 42 5 ml. of concentrated sulphuric acid. When the temperature has fallen to 5°, introduce 50 g. of A.R. chromic anhydride in small portions at such a rate that the temperature does not rise above 10° continue the stirring for 10 minutes after all the chromium trioxide has been added. Pour the contents of the flask into a 3 litre beaker two-thirds filled with crushed ice and almost fill the beaker with cold water. Filter the solid at the pump and wash it with cold water until the washings are colourless. Suspend the product in 250 ml. of cold 2 per cent, sodium carbonate solution and stir mechanically for 10-15 minutes filter (1), wash with cold water, and finally with 10 ml. of alcohol. Dry in a vacuum desiccator the yield of crude p-nitrobenzal diacetate is 26 g. (2), 

Reflux a mixture of 22 5 g. of crude p-nitrobenzal diacetate, 50 ml. of alcohol, 50 ml. of water and 5 ml. of concentrated sulphuric acid for 30 minutes, filter through a fluted paper, and cool the filtrate in ice. Collect the crystals hy suction filtration, wash with cold water, and dry in a vacuum desiccator. The yield of p nitrohenzaldehyde, m.p. 106° is 12 g. (3). 

Heat a suspension of 22 g. of the diacetate in a mixture of 120 ml. of concentrated hydrochloric acid, 190 ml. of water and 35 ml. of alcohol under reflux for 45 minutes. Cool the mixture to 0°, filter the solid with suction, and wash with water. Purify the crude aldehyde by rapid steam distillation (Fig. II, 41, 3) collect about 1500 ml. of distillate during 15 minutes, cool, filter, and dry in a vacuum desiccator over calcium chloride. The yield of pure o-nitrobenzaldehyde, m.p. 44—45°, is 10 g. The crude solid may also be purified after drying either by distillation under reduced pressure (the distillate of rather wide b.p., e.g., 120-144°/3-6 mm., is quite pure) or by dissolution in toluene (2-2-5 ml. per gram) and precipitation with light petroleum, b.p. 40°-60° (7 ml. per ml. of solution). 

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Bromobenzaldehyde and 4-fluorophenylboronic acid were coupled in DMF using tetrakis(triphenylphosphine)palladium(0) as catalyst [85] (see a more extended description in [42]). 

OS 45] [R 17] [noprotocol] For the reaction of 3-bromobenzaldehyde and 4-fluorophenylboronic acid, improved conversion was found for a micro reactor, composed... 

Bromobenzaldehyde from aluminum chloride catalyzed bromination of benzaldehyde, 40, 9 Bromobenzene, conversion to Grignard reagent, 41, 91... 

In the laboratory of D. Ma, the asymmetric synthesis of several metabotropic glutamate receptor antagonists derived from a-alkylated phenylglycines was undertaken. The preparation of (S)-1-aminoindan-1,5-dicarboxylic acid (AIDA) started with the Perkin reaction of 3-bromobenzaldehyde and malonic acid. The resulting ( )-cinnamic acid derivative was hydrogenated and the following intramolecular Friedel-Crafts acylation afforded the corresponding indanone, which was then converted to (S)-AIDA. 

Benzaldehyde, 3-bromo- Benzaldehyde, m-bromo- 3-Bromobenzaldehyde m-Bromobenzaldehyde EINECS 221-526-9 NSC 66828. Liquid bp = 234° Xm = 245, 291 nm (s = 6500, 790, MeOH) insoluble in H2O, slightly soluble in CCI4, very soluble in EtOH, Et20. 

Bromoanl sole 3-Bromoanl sole 4-Bromoanl sole 2-Bromobenzaldehyde 3-Bromobenzaldehyde 4-Bromobenzaldehyde... 

Because of the comparably low reactivity of the methyl group in 274 to be functionalized, formation of diphenylether, which already has this group in a higher oxidized state, is of interest. Therefore 3-bromobenzaldehyde 275 [556], or preferentially its ketal [557, 558], or the ketal of 3-chlorobenzaldehyde [559] were introduced in the Ullmann-coupling ... 

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