Sigma complexes in the pyrimidine series. 5. Reaction of 5-nitromethoxypyrimidines with the anion of malonic acid dinitrile

Cherkasov, V. M.; Remennikov, G. Ya.; Kisilenko, A. A.

doi:10.1007/bf00526093

Cited by 5 publications

(7 citation statements)

References 4 publications

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“…Reactant 2,4,6-trimethoxypyrimidine 32 can be nitrated to 2,4,6-trimethoxy-5-nitropyrimidine 33 in a high isolated yield and purity (Table ). Previously, product 33 was synthesized by the methanolysis of 2,4,6-trichloro- 5-nitrobenzene . Our results represent the first synthesis of 33 by direct nitration.…”

Section: Resultsmentioning

confidence: 66%

Electrophilic Tetraalkylammonium Nitrate Nitration. II. Improved Anhydrous Aromatic and Heteroaromatic Mononitration with Tetramethylammonium Nitrate and Triflic Anhydride, Including Selected Microwave Examples

et al. 2002

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A new one-pot nitration employing tetramethylammonium nitrate and trifluoromethanesulfonic anhydride in dichloromethane to provide a ready source of the nitronium triflate nitrating agent is presented. Rapid and selective nitration with a variety of aromatic and heteroaromatic substrates is achieved resulting in the synthesis of several novel organic compounds. A distinct advantage is the removal of undesired byproducts by aqueous workup. This very mild nitration permits large-scale syntheses and gives high isolated product yields that often require no further purification. This tetramethylammonium nitrate-based nitration also has been applied to microwave-assisted conditions, and the results with several compounds are outlined.

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Section: Resultsmentioning

confidence: 66%

Electrophilic Tetraalkylammonium Nitrate Nitration. II. Improved Anhydrous Aromatic and Heteroaromatic Mononitration with Tetramethylammonium Nitrate and Triflic Anhydride, Including Selected Microwave Examples

et al. 2002

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“…Second, in 4 the protonated pyrimidine ring corresponds to a stable cationic σ-complex. Up until now, only anionic σ-complexes of pyrimidines have been isolated in a stable form. − …”

Section: Resultsmentioning

confidence: 99%

Protonation of the Pyrimidine Ring at the C(5) Position: Formation of a Stable Cationic σ-Complex

2003

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NMR studies showed that, in addition to the expected N(1) protonation, 2,4,6-pyrimidinetriamine, N,N,N',N',N",N"-hexamethyl- (1) could also be protonated at the C(5) position in water, leading to an equilibrium between the C(5) and N(1) protonated forms. Analysis of the NMR titration data gives 6.87 and 6.89 for the pK(a) of the C(5) and N(1) protonation equilibria. Moreover, the reaction of 1 with chloroacetyl chloride leads to a novel 1,1-bis(pyrimidin-5-yl)-2-chloroethene type derivative (4) that is, peculiarly, fully monoprotonated at the C(5) position in either of the pyrimidine rings, forming a stable cationic sigma-complex.

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“…The alkylation of anionic -complexes of the pyrimidine series leads to the formation of a new type of dihydropyrimidines containing nitro and alkyl groups at position 5, which are oxidized to difficultly obtainable 5-alkylpyrimidines (G. Ya. Remennikov) [39].…”

Section: Chemistry Of Pyrimidines and Purinesmentioning

confidence: 97%

Chemistry of heterocyclic compounds at the Institute of Organic Chemistry, National Academy of Sciences of Ukraine (Review)

Lozinskii

Il'chenko

2009

Chem Heterocycl Comp

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Sigma complexes in the pyrimidine series. 5. Reaction of 5-nitromethoxypyrimidines with the anion of malonic acid dinitrile

Cited by 5 publications

References 4 publications

Electrophilic Tetraalkylammonium Nitrate Nitration. II. Improved Anhydrous Aromatic and Heteroaromatic Mononitration with Tetramethylammonium Nitrate and Triflic Anhydride, Including Selected Microwave Examples

Electrophilic Tetraalkylammonium Nitrate Nitration. II. Improved Anhydrous Aromatic and Heteroaromatic Mononitration with Tetramethylammonium Nitrate and Triflic Anhydride, Including Selected Microwave Examples

Protonation of the Pyrimidine Ring at the C(5) Position: Formation of a Stable Cationic σ-Complex

Chemistry of heterocyclic compounds at the Institute of Organic Chemistry, National Academy of Sciences of Ukraine (Review)

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