Heterocyclic carboxamide

Parlow, J. J. Mischke, D. A. Woodard, S. S. Utility of Complementary Molecular Reactivity and Molecular Recognition (CMR/R) Technology and Polymer-Supported Reagents in the Solution-Phase Synthesis of Heterocyclic Carboxamides, /. Org. Chem. 1997,62, 5908. 

Oxicams are a series of A-heterocyclic carboxamides of 1,2-benzothiazine 1,1-dioxides. Piroxicam... 

JJ Parlow, DA Mischke, SS Woodard. Utility of complementary molecular reactivity and molecular recognition (CMR/R) technology and polymer-supported reagents in the solution-phase synthesis of heterocyclic carboxamides. J Org Chem 62 5908-5919, 1997. 

Hydrolysis of amides. Treatment of an aqueous suspension of an amide with 1 eq. of sodium peroxide at 50° (or on a steam bath) added gradually results in hydrolysis within 1 hr. Yields are usually greater than 85%. Extremely water-insoluble amides fail to react. The reaction is particularly valuable for heterocyclic carboxamides when the derived acid is prone to decarboxylation. 

Within the series of 4-hydroxy-1,2-benzothiazine carboxamides represented by the general structure shown below, optimum activity was observed when Ri was a methyl substituent. The carboxamide substituent, R, generally is an aryl or heteroaryl substituent, because alkyl substituents are less active. Oxicams are acidic compounds, with pKa values in the range of four to six. N-heterocyclic carboxamides generally are more acidic than the corresponding N-aryl carboxamides, and this enhanced acidity was attributed (69) to stabilization of the enolate anion by the pyridine nitrogen atom, as illustrated in tautomer A and additional stabilization by tautomer B ... 

As extensions of the findings with compound 132, Lombardino and Wiseman prepared A-heterocyclic carboxamides of 4-hydroxy-2H-l,2-benzothiazine 1,1-dioxide including the potent anti-inflammatory sudoxicam... 

This reagent is commercially available and is presently used for many thionations of carbonyl-containing compounds. This is very versatile and efficient, thionating reagent for aromatic, aliphatic, unsaturated, and heterocyclic carboxamides. Lawesson s reagent can thionate carboxamides in the presence of many functional groups. Treatment of 3-A -acylamino ketones with 1 yielded 4//-l,3-thiazine derivatives 2 and 3-A -thioacylamino ketones 3, respectively. By changing the concentration of 1, selective product has been obtained. The 4/f-l,3-thiazines 2 have been produced predominantly when 1 equiv. of 1 was used, while with 0.5 equiv. of 1 the thioamides 3 have been mainly produced (Scheme 2). ... 

FurutaY, Egawa H, Nomura N (2002) Nitrogen-containing heterocyclic carboxamide derivatives or salts thereof and antiviral agents comprising the same. US 2002013316... 

Heterocyclic Carboxamide Derivatives - In the carrageenin rat paw assay carboxanilides of the oxindole ring (.12) demonstrated antiinflammatory activity somewhat less potent than indomethacin, having long dog plasma half-lives,... 

From a screening using racemic iV-heterocyclic carboxamides as sole sources of nitrogen, three strains bearing stereoselective amidases were isolated and used for the... 

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