Resorcinol, 4-Bromo

Phloroglucinol is readily produced, and with overall 5delds of 50-70%, when starting with 4-chloro resorcinol, which is commercially available. To prepare the mono methyl ether, 4-chloro-3-methoxy phenol can be used. Of course the chlorine atom may also be in one of the two other suitable positions, i.e. the 5- or 6-position, and instead of chlorine in the starting material one of the other halogens may be employed. Useful starting materials thus include 4-chloro resorcinol, 5-chloro resorcinol, 4-bromo resorcinol, 5-bromo resorcinol, 4-chloro-3-methoxy phenol, 5-chloro-3-methoxy phenol, 6-chloro-3-methoxy phenol, 4-bromo-3-methoxy phenol, 5-bromo-3-methoxy phenol, and 6-bromo-3-methoxy... 

Fluorescein is obtained by condensing phthahc anhydride (1 mol) with resorcinol (2 mols) in the presence of anhydrous zinc chloride. The tetra-bromo derivative, readily prepared by the addition of the calculated quantity of bromine, is eosin. 

Bromoresorcinol has been prepared by the monobromination of resorcinol monobenzoate and subsequent hydrolysis, from 2-bromo-5-aminophenol by the diazo reaction, by treating resorcinol with dichlorourea and potassium bromide, and by the bromination of 2,4-dihydroxy benzoic acid followed by decarboxylation. The above procedure is based particularly upon the observations of Rice. ... 

Many color reagents are applicable to the oligosaccharides. Some of those used are ammoniacal silver nitrate,60 resorcinol-hydrochloric acid for inulin hydrolyzates,137 acidic benzidine for maltodextrins,138 Bromo-phenol Blue or p-anisidine-hydrochloric acid for galactosiduronic acids,130 and alkaline copper reagent with phosphomolybdic acid for dextrins.71... 

The extent of C-alkylation as a side reaction in etherification varies about 1% of allyl 2-allylphenyl ether is formed when phenol is used in the acetone and potassium carbonate method with allyl bromide with cinnamyl bromide or 7,7-dimethylallyl bromide the extent of C-alkylar tion is greater.16 A complicated mixture of C- and O-alkylation products results from the treatment of phenol with 4-bromo-2-hexene and 4-chloro-2-hexene. 9 4-Hexenylresordnol has been obtained in about 40% yield from the reaction of l-bromo-2-hexene, resorcinol, and potassium carbonate in boiling acetone.99 An appreciable amount of C-alkylation occurs when 2,6-dimethyIphenol is treated with allyl bromide and sodium ethoxide in ethanol.70 Since, in general, the ampunt of C-alkylation is greatly increased by carrying out the alkylation on the sodium salt of the phenol in benzene,16 this method is unsuitable for the preparar tion of allyl aryl ethers. 

C11H7BroT 5-bromo-1-naphthalenecarboxylic acid 16726-67-3 25.00 1.5651 2 21600 C11H9N302 4-(2-pyridylazo)resorcinol 1141-59-9 25.00 1.3257 2... 

C6Ds02f Resorcinol (a form), 46B, 97 C6Dg02, Resorcinol ip form), 46B, 97 CeHClsO, Pentachlorophenol, 27, 903 CsH2Cla02, Tetrachlorohydroquinone, 27, 901 32B, CeH3BrN205, 2-Bromo-4,6-dinitrophenol, 41B, 129 C6H3CIN2O5, 2-Chloro-4,6-dinitrophenol, 41B, 130 C6H, C1N03, 2-Nitro-4-chlorophenol, 42B, 85 C6H Cl20, 2,3-Dichlorophenol, 42B, 85... 

Bromoresorcinol may be similarly prepared from /3-resor-cylic acid [27]. To obtain 2-bromo- or 2-chloro-resorcinol, /3-resorcylic acid is successively nitrated and halogenated. The resulting product is then reduced, deaminated, and finally decarboxylated (H2O, 100 , 3hr) to give the desired compound [28]. 

Also obtained by reaction of acetic add on 2-bromo-resorcinol with zinc chloride (Nencki reaction) (26%) [1840]. 

The compound corresponding to XIII), 4,6-dichloro-5-methylresorcinol XIV) shows some anti-inflammatory activity, whilst other halogenated 5-methylresorcinols (e.g. XV) are also active. It was found that the resorcinol nucleus is the best structure for activity, since the bromo derivatives from 2-methylhydroquinone XVI) and from 4-methylcatechol XVII) are... 

---