- Highly efficient nitration of phenolic compounds by zirconyl nitrate
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Zirconyl nitrate was found to be an excellent reagent in the nitration of phenol and substituted phenols to give nitrated phenols. This procedure works efficiently on most of the examples at room temperature yielding nitro derivatives in fair to good yields with high regioselectivity.
- Selvam, J. Jon Paul,Suresh,Rajesh,Reddy, S. Ravinder,Venkateswarlu
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p. 2507 - 2509
(2007/10/03)
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- Selective nitration of phenol derivatives
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Process for preparing 4-nitrophenol derivatives of formula (IV) with high selectivity, which comprises converting phenols to diphenyl oxalate derivatives of formula (III) and conducting nitration reaction and hydrolysis to give said 4-nitrophenol derivatives. STR1 In the above formulae, R is, the same or different from each other, an alkyl group having 1 to 4 carbon atoms; a halogen atom; an alkoxy group having 1 to 4 carbon atoms; a formyl group; a nitrile group; --COOR1 (R1 is an alkyl group having 1 to 4 carbon atoms); --CONR2 R3 (R2 and R3 are, the same or different from each other, hydrogen atom(s) or alkyl group(s) having 1 to 4 carbon atoms); or --COR4 (R4 is an alkyl group having 1 to 4 carbon atoms), and R is not substituted at the 4-position of the phenyl ring and not substituted at the 2- and 6-positions of the phenyl ring at the same time, and, n is 1, 2 or 3.
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- Cerium(IV) induced oxidative coupling of simple phenols in the presence and absence of hydrogen peroxide: A comparative study of product distribution
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The reaction of cerium(IV) ammonium nitrate with simple phenols (2-, 3- and 4-methylphenols) has been examined in the presence and absence of hydrogen peroxide.It has been observed that though the oxophilicity of cerium(IV) can be controlled by addition of hydrogen peroxide in the reaction medium, there is also a difference in the nature of products formed.The reaction can be used to obtain new terphenyls (3a, 3b and 3e), biphenyls (2a, and 2e), 2-hydroxy-1,9-dimethyl-7-nitro-dibenzyl-p-dioxin (4) and 3,7-dimethyl-1,9-dinitrodibenzofuran (5) in acceptable net yields.
- Chakrabarty, Kakoli,Chawla, H. Mohindra,Suresh, Valiya Veettil
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p. 266 - 274
(2007/10/02)
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- Reaction of cerium(IV) ammonium nitrate with simple phenols in a silica gel matrix
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The oxophilicity of cerium(IV) ammonium nitrate is moderated by the addition of hydrogen peroxide.The reaction with simple phenols becomes regioselective when carried out in a silica gel matrix.The methodology has been employed for the synthesis of new functionalized terphenyls and biphenyls.
- Chakrabarty, K,Chawla, H M,Suresh, V V
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p. 464 - 466
(2007/10/02)
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- Water-soluble trisazo 8-amino-naphthol-1 dyes
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Very effective direct dyeing of cotton and other hydroxyl- or nitrogen-containing fibers is effected with water-soluble triasazo dyes having the formula: where A is a radical of a diazoconstituent and A3 is a radical of a coupling constituent STR1 and A1 or A2 or both can have their azo linkages reversed. These dyes are very fast particularly to washing and to perspiration, and are so effective with cotton that dye baths for such use are rapidly exhausted and the disposal of used bath is less of a problem.
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