- Direct synthesis of esters and amides from unprotected hydroxyaromatic and -aliphatic carboxylic acids
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A facile method for the activation of hydroxy-substituted carboxylic acids using benzotriazole chemistry without prior protection of the hydroxy substituents is presented. The N-acylbenzotriazole intermediates 2a-g, 6a-d, and 9a-c have been used for high-yielding synthesis of both aliphatic (3a-1) and aromatic (7a-h, 10a-f) hydroxy carboxamides. High yields of aromatic hydroxy esters 12a-h and 13a-i were obtained using either neat alcohols in neutral microwave conditions or nucleophilic alkoxides and the intermediate N-(arylacyl)benzotriazoles. Moderate yields were obtained in the case of aliphatic hydroxy esters 11a,b and thiolesters 11e-g from the intermediates 2a-c.
- Katritzky, Alan R.,Singh, Sanjay K.,Cai, Chunming,Bobrov, Sergey
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p. 3364 - 3374
(2007/10/03)
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- Nematocidal principles in 'oakmoss absolute' and nematocidal activity of 2,4-dihydroxybenzoates
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Nematocidal principles obtained from oakmoss absolute were identified as methyl 2,4-dihydroxy-3,6-dimethylbenzoate (2), ethyl 3-formyl-2,4-dihydroxy-6-methylbenzoate (4), and ethyl 5-chloro-3-formyl-2,4-dihydroxy-6-methylbenzoate (7). In relation to their structures, the nematocidal activity of 2,4-dihydroxybenzoates of methyl to tetradecyl was tested and the strongest activity was found in the octyl ester (minimal lethal concentration=13 μM).
- Ahad,Goto,Kiuchi,Tsuda,Kondo,Sato
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p. 1043 - 1046
(2007/10/02)
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