- Direct conversion of carboxylic acids to various nitrogen-containing compounds in the one-pot exploiting curtius rearrangement
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Herein we report, a single-pot multistep conversion of inactivated carboxylic acids to various N-containing compounds using a common synthetic methodology. The developed methodology rendered the use of carboxylic acids as a direct surrogate of primary amines, for the synthesis of primary ureas, secondary/tertiary ureas, O/S-carbamates, benzoyl ureas, amides, and N-formyls, exploiting the Curtius reaction. This approach has a potential to provide a diversified library of N-containing compounds, starting from a single carboxylic acid, based on the selection of the nucleophile.
- Kumar, Arun,Kumar, Naveen,Sharma, Ritika,Bhargava, Gaurav,Mahajan, Dinesh
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p. 11323 - 11334
(2019/09/10)
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- An investigation on practical synthesis of carboxylic acid derivatives using p-toluenesulfonyl chloride
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Carboxylic acid derivatives are well recognized as important class of reagents frequently used in the preparation of a variety of fine or special chemicals such as amides, esters, peptides, drugs, and dyes. Although several methods were developed for the preparation of these compounds, many of them present difficulties, including low yield, high reaction temperature, harsh reaction conditions, tedious work-up, and incompatibility with scale-up. Methods: The synthesis of carboxylic anhydrides is developed through the reaction of carboxylic acids with TsCl in the presence of K2CO3 and acetonitrile as a solvent under ultrasound irradiation and conventional conditions. In addition, one-pot synthesis of acyl azides was carried out in the presence of produced carboxylic anhydrides and the addition of sodium azide under identical condition. Results: A series of carboxylic anhydrides and acyl azides were synthesized using TsCl under ultrasound irradiation and conventional stirring with simple procedure, mild reaction conditions, high yields, and scale-up ability without any restriction. In most cases, the reaction under ultrasound irradiation was better in both yields and the reaction times compared to the conventional method. Conclusion: A convenient method has been developed for the preparation of carboxylic anhydrides and acyl azides under ultrasound irradiation and conventional stirring. The present method is practical and a highly effective alternative for previous reports. The major advantages of this method are: (i) simplicity of the procedure (ii) high yields and high purity of product (iii) scale-up capacity without considerable limitation in conventional system. Under ultrasound irradiation short reaction times as compared to conventional method are observed; yields are comparable to or better than conventional method.
- Eskandari, Parvin,Kazemi, Foad
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p. 431 - 439
(2017/07/24)
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- Novel tetrahydropyrido[1,2-a]isoindolone derivatives (valmerins): Potent cyclin-dependent kinase/glycogen synthase kinase 3 inhibitors with antiproliferative activities and antitumor effects in human tumor xenografts
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The development of CDK and GSK3 inhibitors has been regarded as a potential therapeutic approach, and a substantial number of diverse structures have been reported to inhibit CDKs and GSK-3β in recent years. Only a few molecules have gone through or are currently undergoing clinical trials as CDK and GSK inhibitors. In this paper, we prepared valmerins, a new family containing the tetrahydropyrido[1,2-a]isoindone core. The fused heterocycle was prepared with a straightforward synthesis that was functionalized by a (het)arylurea. Twelve valmerins inhibited the CDK5 and GSK3 with an IC50 100 nM. A semiquantitative kinase scoring was realized, and a cellular screening was done. At the end of our study, we investigated the in vivo potency of one valmerin. Mice exhibited good tolerance to our lead, which proved its efficacy and clearly blocked tumor growth. Valmerins appear also as good candidates for further development as anticancer agents.
- Boulahjar, Rajaa,Ouach, Aziz,Matteo, Chiurato,Bourg, Stephane,Ravache, Myriam,Guével, Rémy Le,Marionneau, Séverine,Oullier, Thibauld,Lozach, Olivier,Meijer, Laurent,Guguen-Guillouzo, Christiane,Lazar, Sa?d,Akssira, Mohamed,Troin, Yves,Guillaumet, Gérald,Routier, Sylvain
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p. 9589 - 9606
(2013/01/16)
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- Extremely simple but long overlooked: Generation of α-Azido alcohols by hydroazidation of aldehydes
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Discovered by accident: Just because an example of a simple substructure cannot be found in literature does not mean that corresponding compounds are not readily accessible. α-Azido alcohols like 1-azidoethanol have now been prepared and isolated. Copyright
- Banert, Klaus,Berndt, Christian,Firdous, Samia,Hagedorn, Manfred,Joo, Young-Hyuk,Rueffer, Tobias,Lang, Heinrich
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supporting information; experimental part
p. 10206 - 10209
(2011/02/27)
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- Lithium/DTBB-induced reduction of N-alkoxyamides and acyl azides
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A series of N-alkoxyamides and N-methoxy-N-methylamides (Weinreb amides) have been subjected to dealkoxylation by reductive cleavage of the N-O bond with lithium powder and a catalytic amount of DTBB (10 mol%) at room temperature, leading to the corresponding amides. When the reaction is performed under reflux conditions, the corresponding alkanes, resulting from a formal deaminocarbonylation process, are obtained. This methodology applied to acyl azides furnished the corresponding primary amides.
- Yus, Miguel,Radivoy, Gabriel,Alonso, Francisco
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p. 914 - 918
(2007/10/03)
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- One-flask conversion of carboxylic acids into carbamoyl azides
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Carbamoyl azides can be generated in high yields from the corresponding carboxylic acid and triphenylphosphine by adding NCS, followed by sodium azide and triethylamine hydrochloride.
- Froyen
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p. 4549 - 4561
(2007/10/03)
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- Modified Pyridinium Chlorochromate Oxidation of Aldehydes to Carbamoyl Azides/Acyl Azides or Carboxylic Acids
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Aldehydes are transformed into carbamoyl azides/acyl azides by pyridinium chlorochromate in the presence of sodium azide.Comparable oxidations modified with sodium cyanide generate carboxylic acids from simple aliphatic aldehydes whereas conjugated aldehydes are undeactive.
- Reddy, P. Satyanarayana,Yadagiri, Pendri,Lumin, Sun,Shin, Dong-Soo,Falck, J. R.
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p. 545 - 552
(2007/10/02)
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