Carboxamides acidity

Another version of the o-aminobenzyl anion synthon is obtained by dilithi-ation of A-f-Boc-protected o-alkylanilines. These intermediates are C-acylated by DMF or A"-methoxy-At-melhyl carboxamides, leading to either 3- or 2,3-disubstituted indoles. In this procedure dehydration is not spontaneous but occurs on brief exposure of the cyelization product to acid[4]. Use of CO as the electrophile generates oxindoles. 

Amides. For primary amides the suffix -amide is added to the systematic name of the parent acid. For example, CH3—CO—NHj is acetamide. Oxamide is retained for HjN—CO—CO—NHj. The name -carboxylic acid is replaced by -carboxamide. 

CbHORINE OXYGEN ACIDS AND SALTS - CbHOROUS ACID, CbHORITES, AND CbHORINE DIOXIDE] (Vol 5) [l-(2,6-Diethylphenyl)-imida2ole-5-carboxamide]... 

Acrylamide, C H NO, is an interesting difiinctional monomer containing a reactive electron-deficient double bond and an amide group, and it undergoes reactions typical of those two functionalities. It exhibits both weak acidic and basic properties. The electron withdrawing carboxamide group activates the double bond, which consequendy reacts readily with nucleophilic reagents, eg, by addition. 

Specialty Isocyanates. Acyl isocyanates, extensively used in synthetic appHcations, caimot be direcdy synthesized from amides and phosgene. Reactions of acid haUdes with cyanates have been suggested. However, the dominant commercial process utilizes the reaction of carboxamides with oxalyl chloride [79-37-8]. CycHc intermediates have been observed in these reactions which generally give a high yield of the desired products (86). 

Table 3 gives the corresponding physical properties of some commercially important substituted pyridines having halogen, carboxyHc acid, ester, carboxamide, nitrile, carbiaol, aminomethyl, amino, thiol, and hydroxyl substituents. 

Pyridinecarbonitriles, -carboxamides, and -carboxylic Acids. 3-Cyanopyridine (25) is used for the production of niaciu (27), or vitamin 4-Cyanopyridine (15) is used for making the antitubercular dmg isonia2id (31) (101). 

Pyridine carboxamide [98-92-0] (nicotinamide) (1) and 3-pyridine carboxylic acid [59-67-6] (nicotinic acid) (2) have a rich history and their early significance stems not from their importance as a vitamin but rather as products derived from the oxidation of nicotine. In 1867, Huber prepared nicotinic acid from the potassium dichromate oxidation of nicotine. Many years later, Engler prepared nicotinamide. Workers at the turn of the twentieth century isolated nicotinic acid from several natural sources. In 1894, Su2uki isolated nicotinic acid from rice bran, and in 1912 Funk isolated the same substance from yeast (1). 

The result of this biosynthesis is that the product is nicotinic acid mononucleotide rather than free nicotinic acid. Ingested nicotinic acid is converted to nicotinic acid mononucleotide which, in turn, is converted to nicotinic acid adenine dinucleotide. Nicotinic acid adenine dinucleotide is then converted to nicotinamide adenine dinucleotide. If excess nicotinic acid is ingested, it is metabolized into a series of detoxification products (Fig. 4). Physiological metabohtes include /V-methylnicotinamide (19) and A/-methyl-6-pyridone-2-carboxamide (24) (1). 

Pyridazines with a hydroxy group at an a- or y-position to a ring nitrogen atom, i.e. 3-and 4-hydroxypyridazines (4) and (5), exist predominantly in the oxo form. This conclusion is based on spectroscopic evidence from UV spectra of unsubstituted compounds and their A-methyl and O-methyl derivatives in alkaline, neutral and acidic solutions. In some instances, as for example for 6-oxo-l,6-dihydropyridazine-3-carboxamide, there is also evidence from X-ray analysis <54AX199, 63AX318). Maleic hydrazide and substituted maleic hydrazides exist in the monohydroxymonooxo form (6). 

Pyridazinecarboxamides are prepared from the corresponding esters or acid chlorides with ammonia or amines or by partial hydrolysis of cyanopyridazines. Pyridazinecarboxamides with a variety of substituents are easily dehydrated to nitriles with phosphorus oxychloride and are converted into the corresponding acids by acid or alkaline hydrolysis. They undergo Hofmann degradation to give the corresponding amines, while in the case of two ortho carboxamide groups pyrimidopyridazines are formed. 

The treatment of 3-benzoyl-2-phenylisoxazolidine with strong base generated an aldehyde and a ketimine <74X1121). Under these conditions dimethyl 2-a-methoxyisoxazolidine-3,3-dicarboxylic acid (186) produced isoxazoline-2-carboxylic acid. Reaction of the monomethyl amide (187) gave the corresponding isoxazoline-2-carboxamide (Scheme 60). CD was used in the conformational studies <79X213). 

Selenophene-2-carboxamide, JV,JV-dimethyl-PE, 4, 25 (76JCS(P2)276> Selenophene-2-carboxylic acid microwave, 4, 4, 937 (62AX737) pK 4, 71 (77AHC(21)119>... 

Tellurophene-2-carboxamide, JV, N-dimethyl-PE, 4, 25 <76JCS(P2)276> Tellurophene-2-carboxylic acid... 

Benzo[c]furan, 1,3,4,7-tetraphenyl-steric hindrance, 4, 542 synthesis, 4, 683 Benzo[b]furan-3-acetic acid synthesis, 3, 686 Benzo[b]furan-3-amine, 2-acyl-tautomerism, 4, 648 Benzo[b]furan-2-carboxamides synthesis, 3, 685... 

H-Chromene, 2-ethyl-3-phenyl-synthesis, 3, 764 4H-Chromene, 2-phenyl-synthesis, 3, 763 4H-Chromene, 2,4,4-trimethyl-addition reactions, 3, 669 2 H-Chromene-3-carboxamide reduction, 3, 675 2H-Chromene-3-carboxylic acid methyl ester alcoholysis, 3, 668... 

C NMR, 6, 398 molecular dimensions, 6, 397 tautomerism, 6, 404 Furoxan-3-carbohydra2ide intramolecular hydrogen bonding, 6, 396 Furoxan-3-carboxamide intramolecular hydrogen bonding, 6, 396 Furoxancarboxylic acids reactions, 6, 413 with nucleophiles, 6, 406 Furoxan-3,4-dicarbaldoxime synthesis, 6, 409 Furoxanoaaines fused... 

Imidazole-5-carboxamide, l-methyl-4-nitro-mass spectra, 5, 359 Imidazole-4-carboxanilide, 1-methyl-synthesis, 5, 435 Imidazolecarboxylic acid, vinyl-polymers, 1, 281 Imidazole-2-carboxylic acid chlorination, 5, 398 mass spectra, 5, 360 synthesis, 5, 474... 

Pyrrole-2-carboxamide, N,N-dimethyl-conformation, 4, 194 Pyrrole-3-carboxamide, N,N-dimethyl-conformation, 4, 194 Pyrrolecarboxamides synthesis, 4, 242 Pyrrole-2-carboxamides synthesis, 4, 148, 360 Pyrrolecarboxylhydrazides Curtius degradation, 4, 362 Pyrrole-2-carboxylic acid, l-benzyl-3-hydroxy-ethyl ester... 

At low temperature a 1 1 adduct of thioacetic acid and an enamine could be prepared (709). The previously described reaction of aminomethylene ketones with hydrogen peroxide was extended to bisaminomethylene compounds. However, acylated cyclohexenamines led to cyclopentane-carboxamides (770), Trichloromethyl adducts of enamines and the rearranged amine derivatives were described in a further study (777). 

In addition to thiodiglycolic acid esters, the use of bis(cyanomethyl)sulfide in the Hinsberg reaction has facilitated the preparation of 5-cyano-thiophene-2-carboxamides. Thus, the condensation of biacetyl with bis(cyanomethyl)sulfide resulted in the efficient preparation of 10 (94% yield). 

The second procedure of this type was first described by Yamada et They used the diamidine of malonic acid (175) or cyanace-tamide (176) to prepare l-benzyl-5-amino-u-triazole-4-carboxamide... 

The A-substituted derivatives of 4-oxo-4//-pyrido[l,2-n]pyrimidine-3-carboxamides and -3-acetamides and l,6-dimethyl-4-oxo-1,6,7,8-tetrahy-dro-4//-pyrido[l,2-n]pyrimidine-3-carboxamide were prepared by treatment of the appropriate 3-carboxylic acids and acetic acid, first with an alkyl chloroformate in the presence ofNEt3 in CHCI3 below — 10°C, then with an amine (98ACH515). A-Phenethyl and A-[2-(3,4-dimethoxyphenyl)ethyl] derivatives of 6-methyl-6,7,8,9-tetrahydro-4//-pyrido[l, 2-n]pyrimidine-3-acetamide were obtained in the reaction of 6-methyl-6,7,8,9-tetrahydro-4//-pyrido[l,2-n]pyrimidine-3-acetic acid and phenethylamines in boiling xylene under a H2O separator. Hydrazides of 4-oxo-4//- and 4-oxo-6,7,8,9-tetrahydro-4//-pyrido[l, 2-n]pyrimidine-3-acetic acid were prepared from the appropriate ester with H2NNH2 H2O in EtOH. Heating 4-oxo-4//- and 6-methyl-4-oxo-6,7,8,9-tetrahydro-4//-pyrido[l, 2-n]pyrimidine-3-acetic hydrazides in EtOH in the presence of excess Raney Ni afforded fhe appropriafe 4-oxo-6,7,8,9-fefrahydro-4//-pyrido[l,2-n]pyrimidine-3-acefa-mide. In the case of the 4-oxo-4// derivative, in addition to N-N bond... 

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