A fast and mild method for the nitration of aromatic rings

Bak, Radoslaw R.; Smallridge, Andrew J.

doi:10.1016/s0040-4039(01)01378-8

Cited by 85 publications

(44 citation statements)

References 4 publications

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“…Other examples involve the use of lanthanide (III), zirconium(IV) or hafnium(IV) triflate salts as catalysts of nitric acid nitration [16]. Iron (III)2,4pentanedionate [17,18] and zirconium(IV) 2,4-pentanedionate [19] have also been used as catalysts in the presence of dinitrogen pentoxide.…”

Section: Introductionmentioning

confidence: 99%

Combination of Transition Metals-(2,4-Pentanedionate) and P2O5 as a Regioselective Catalytic System for Nitric Acid Nitration of Ar-Himachalene

Hossini¹,

Harrad²,

Boualy³

et al. 2011

GSC

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A practical system of metals-(2,4-pentanedionate) (M(acac) n (M= Fe, Zn, Co and V)) and P 2 O 5 in the presence of HNO 3 catalyzes regioselective nitration of ar-himachalene 1 to mono-nitro-ar-himachalene 2 in moderate to high yields. Under mild conditions, the selectivity of nitration of 1 to 2 is excellent compared to the classical method using the nitro-sulphuric mixture HNO 3 /H 2 SO 4 , both mono-and di-nitro-ar-himachalene 2 and 3 are obtained. The reaction offers a very good method for the preparation of nitro-aromatic compounds and provides a useful entry to new functionalized terpenic products.

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Section: Introductionmentioning

confidence: 99%

Combination of Transition Metals-(2,4-Pentanedionate) and P2O5 as a Regioselective Catalytic System for Nitric Acid Nitration of Ar-Himachalene

Hossini¹,

Harrad²,

Boualy³

et al. 2011

GSC

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“…Alternative systems developed recently for nitration of deactivated aromatics include nitric acid in the presence of P 2 O 5 supported on silica gel [18], nitrogen dioxide at low temperatures in the presence of ozone [19], N 2 O 5 in the presence of Fe(acac) 3 as a catalyst [20], urea nitrate and nitrourea [21], nitroguanidine and ethylene glycol dinitrate in concentrated acid [22], vanadium(V) oxytrinitrate in dichloromethane at room temperature [23], and nitric acid in the presence of MCM-41-supported metal bis[(perfluoroalkyl)sulfonyl]imides in dichloroethane [24]. However, such reagents still give mainly the meta-products and moreover, ortho-isomers are often formed in relatively high proportions.…”

Section: Introductionmentioning

confidence: 99%

Regioselective Nitration of Deactivated Mono-Substituted Benzenes Using Acyl Nitrates Over Reusable Acidic Zeolite Catalysts

2010

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Nitration of benzonitrile was investigated using a nitric acid/acid anhydride/zeolite catalyst system under different reaction conditions. Trifluoroacetic and chloroacetic anhydrides were found to be the most active among the anhydrides tried. Also, zeolites Hb and Fe 3? b (Si/ Al = 12.5) were found to be the most active catalysts. For example, nitration of benzonitrile with trifluoroacetyl nitrate under reflux conditions in dichloromethane gave 3-and 4-nitrobenzonitriles in quantitative yield, of which the para-isomer represented 24-28%. The yield of para-isomer was improved to 33% when passivated Hb was used under similar reaction conditions. This is easily the most para-selective nitration of benzonitrile ever recorded. Also, no ortho-isomer was formed under the conditions tried. The zeolite can be easily recovered, regenerated by heating and reused up to six times to give results similar to those obtained with a fresh sample of the catalyst. The nitration system was applied successfully to a range of deactivated mono-substituted benzenes to give para-isomers in significantly higher proportions than in the corresponding traditional nitration reactions.

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“…; Table 1, entries 19,20). The observed inversion of ortho/para ratio was attributed to high acidity of reaction medium rather than to nitrating agent origin.…”

Section: Bmentioning

confidence: 96%

“…cerium(III) nitrate, 18 N 2 O 5 (ref. 19 ), NO 2 /O 3 mixture, 20 acetyl nitrate, 21 amyl nitrate 22 (and other mixed anhydrides and esters), N-nitropyrazole, 23 nitronium salts, silver nitrate in the presence of Lewis acids, N-nitropyridinium and N-nitroquinolinium and nitro or nitrito onium salts (for review see ref. 24 ), guanidinium nitrate, 25a nitroguanidine, urea nitrate or nitrourea.…”

Section: Introductionmentioning

confidence: 99%

Directing effects in nitration of 1-adamantyl bearing aromatic ketones

Vícha¹,

Kuřitka²,

Rouchal³

et al. 2009

Arkivoc

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Nitration of four 1-adamantyl bearing aromatic ketones with mixed acid, acetyl nitrate, silver nitrate and guanidine nitrate was studied under various conditions. The ketones with conjugated carbonyl group or with a benzyl group were examined and a considerably high amount of ortho isomer was observed in all cases. The proportion of ortho nitration showed the same trends for both examined groups of ketones. Unprecedently, the ortho isomer was formed quantitatively upon the reaction of 1-(1-adamantyl)-3-phenylpropan-2-one with acetyl nitrate in acetic anhydride. Influence of electronic, steric and complexation effect of carbonyl group on regioselectivity is discussed. An alternative reaction pathway including complexation of nitrating agent and a pre-equilibrium of protonated and nitronium coordinated carbonyl in particular is suggested to play crucial and general role in nitrations of aromatic carbonyl compounds.

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A fast and mild method for the nitration of aromatic rings

Cited by 85 publications

References 4 publications

Combination of Transition Metals-(2,4-Pentanedionate) and P2O5 as a Regioselective Catalytic System for Nitric Acid Nitration of Ar-Himachalene

Combination of Transition Metals-(2,4-Pentanedionate) and P2O5 as a Regioselective Catalytic System for Nitric Acid Nitration of Ar-Himachalene

Regioselective Nitration of Deactivated Mono-Substituted Benzenes Using Acyl Nitrates Over Reusable Acidic Zeolite Catalysts

Directing effects in nitration of 1-adamantyl bearing aromatic ketones

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