- Efficient access to polysubstituted amidines, benzimidazoles and pyrimidines from amides
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Polysubstituted amidines, benzimidazoles and pyrimidines were synthesized via the electrophilic activation of amides with trifluoromethanesulfonic anhydride and 2-chloropyridine. The one-pot protocol is concise and efficient and the substrates are readily available.
- Wang, Jing,He, Zhenxing,Chen, Xiaopeng,Song, Wangze,Lu, Ping,Wang, Yanguang
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experimental part
p. 1208 - 1214
(2010/04/02)
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- INTERMOLECULAR IMIDOYLATION REACTION OF THE CARBOXAMIDE GROUP
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Reactions of N-monosubstituted benzamides with Ph3PBr2 and Et3N in refluxing CH2Cl2 for 0.5 - 5 hours give good yields of N,N'-disubstituted-N-acylamidines.The latter compounds may be regarded as intermolecular N-imidoylation products of the amide group.Under the same reaction conditions, N-monosubstituted amides containing C-H bonds adjacent to the carbonyl function and N-monosubstituted formamides are dehydrated to ketenimines and isonitriles, respectively.Treatment of N-methyl-benzamide with Ph3PBr2 and Et3N leads to the formation of an intermediate whose ir spectrum is consistent with the N,N,N-triethyl-N'-methylbenzamidinium salt structure.A substance with identical spectroscopic characteristics was obtained on treatment of N-methyl-α-bromobenzylideneammonium bromide with Et3N.Products of the reaction of 5- and 6-membered lactams with Ph3PBr2 and Et3N are inactive as imidoylating agents; consequently, these lactams do not undergo self-condensation to N-imidoylation products, but they can participate in the imidoylation reactions as nucleophiles subjected to imidoylation.In contrast to the 5- and 6-membered lactams, ε-caprolactam undergoes self-condensation to the expected N-imidoylation product.Possible mechanistic pathways for the imidoylation reaction of the amide group have been suggested.
- Mazurkiewicz, Roman
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p. 439 - 450
(2007/10/02)
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- The side-chain acylamination of alicyclic nitrones. A new synthesis of an α-amino acid
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2,4,4-Trimethyl-Δ1-pyrroline-1- (4) and 2-n-butyl-4,4-dimethyloxazoline-3-oxide (6) are acylaminated in the presence of base at the α-position of the side-chain at C-2 to give 5 and 10, respectively.Ethanolysis of 10 gives the corresponding α-amino ester (11) in good yield
- Abramovitch, Dorota A,,Abramovitch, Rudolph A.,Benecke, Herman
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