Carboxamides hydrolysis

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. 

Pyrimidine-5-carboxamide, 4-amino-purine synthesis from, 5, 582 Pyrimidine-5-carboxamide, 4-amino- N- pheny synthesis, 3, 122 Pyrimidinecarboxamides Curtius degradation, 3, 82 dehydration, 3, 82 Hofmann degradation, 3, 82 hydrolysis, 3, 81 reactions, 3, 81 synthesis, 3, 127 Pyrimidinecarboxamides, thio-synthesis, 3, 128... 

Other methods for the preparation of cyclohexanecarboxaldehyde include the catalytic hydrogenation of 3-cyclohexene-1-carboxaldehyde, available from the Diels-Alder reaction of butadiene and acrolein, the reduction of cyclohexanecarbonyl chloride by lithium tri-tcrt-butoxy-aluminum hydride,the reduction of iV,A -dimethylcyclohexane-carboxamide with lithium diethoxyaluminum hydride, and the oxidation of the methane-sulfonate of cyclohexylmethanol with dimethyl sulfoxide. The hydrolysis, with simultaneous decarboxylation and rearrangement, of glycidic esters derived from cyclohexanone gives cyclohexanecarboxaldehyde. 

The respective amide was prepared from 7-substituted 5-oxo-2,3-dihydro-5//-pyrido[l,2,3-de]-l,4-benzoxazine-6-carboxylic acids via acid chlorides with different benzylamines (00M1P3). 6-Carboxamides were N-benzylated, and a side-chain phenolic hydroxy group was O-alkylated. 7-Aryl-5-oxo-2,3-dihydro-5//-pyrido[l, 2,3-r/e]-1,4-benzoxazine-6-carboxylic acid was obtained from the ethyl ester by alkalic hydrolysis. 

A side chain carboxyl group in perhydropyrido[l,2-a]pyrazines was obtained from an ester group by acidic or alkalic hydrolysis. A side chain carboxyl group was converted into a carboxamide group by the treatment with an amine in the presence of 1-hydroxybenzotriazole (OOJAP(K)OO/ 86659). 

A number of diarylmethyl alkylpiperazines, such as, for example lidoflazine, have found use as coronary vasodilators for the treatment of angina. The most recent of these interestingly incorporates a 2,6-dichloroaniline moiety reminiscent of antiarrhythmic agents. Treatment of the piperazine carboxamide 124 with acetone leads to formation of the nitrogen analogue of an acetal, the aminal 125. Alkylation of the remaining secondary nitrogen with chloroamide 126 leads to the intermediate 127. Exposure to aqueous acid leads to hydrolysis of the aminal function... 

Benz[l,2-e][l,3]oxazin[3,4-a]azepin-6-one (15) is cleaved rapidly in cold ethereal ethylamine to /V.A-diethyl-2-(2-hydroxyphcnyl)-l//-azepinc-1-carboxamide (90% mp 121 -122°C), whereas acidic hydrolysis yields the intramolecularly hydrogen bonded 2-(2-hydro-xyphenyl)-3//-azepine (16).156... 

We have investigated the reaction of NH phosphinous amides with diphenyl-cyclopropanone. The products were unequivocally identified as the corresponding p-phosphinyl carboxamides 27 resulting from the hydrolysis of a presumed heterocyclic intermediate (Scheme 28) These results await publication. 

On the other hand, the reaction of 3-,sec-aminophenols (71) with phthalic anhydride does not give the corresponding keto acids (72). The keto acids (72) having a secondary amino group at 4-position are prepared by the reaction of 3-sec-aminophenols (71) with phthalimide at 150-220°C in the presence of boric acid, followed by hydrolysis of the intermediate carboxamide with aqueous sodium hydroxide (Eq. 3). 

The hydrolysis leads to 4-aminoimidazole-5-carboxamide, which under certain conditions can react with various partners (e.g., HCN, dicyan or formamidine) to give purines (i.e., adenine, guanine, hypoxanthine and diaminopurine). 

The carboxyl group of 2-[4-(4-carboxybenzoyl)benzyloxy]-3-methyM77-pyrido[l,2- ]pyrimidin-4-one, prepared by hydrolysis of the methyl ester, was reacted first with (Et02C)20 in DMF at room temperature and then with 4-phenylpiperazine and 4-piperidinopiperidine to give the appropriate amide derivatives <1996EPP733633>. The N-substituted derivatives of 4-oxo-477-pyrido[l,2-tf]pyrimidine-3-carboxamides and -3-acetamides and 1,6-dimethyl-4-oxo-l,6,7,8-tetrahydro-477-pyrido[l,2-tf]pyrimidine-3-carboxamide were prepared by treatment of the appropriate... 

The 1,3-dipolar cycloaddition of a variety of aromatic and aliphatic nitrile oxides to 2.5-/ra//.v-2.5-diphenylpyrrolidine-derived acrylamide and cinnamamide 399, efficiently affords the corresponding 4,5-dihydroisoxazole-5-carboxamides 400 in highly regio- and stereoselectivity (Scheme 1.47). Acid hydrolysis of these products affords enantiopure 4,5-dihydroisoxazole-5-carboxylic acids 401 (443). 

Other transformations of the substituents on the N-l atom were also reported <1997JOC7288> (Scheme 9) hydrolysis of the 5-cyano group of derivative 29 to a carboxamide 30 has also been reported. 

The bromodeoxyaldonolactones have been used for the preparation of aminodeoxy aldonic acids and aminodeoxy sugars via azido derivatives (45,46). Likewise, a- and /J-aminopolyhydroxy acids have been prepared by treatment of the bromodeoxyaldonolactones with liquid ammonia (47). Thus, 3-amino-3-deoxy-D-threonic acid and 3-amino-3-deoxy-D-arabin-onic acid (40b) were obtained from 2-bromo-2-deoxy-L-threono- or D-xy-lono-1,4-lactone (38). It was shown that 2,3-epoxy carboxamides (namely, 39) are intermediates of the reaction. Heating at 90° for long periods led to the 3-amino-3-deoxyaldonamides, which upon acid hydrolysis yielded the corresponding aldonic acids. 

The catalysed two-phase alkylation of carboxamides has the advantages of speed and simplicity over the traditional procedures and provides a valuable route to secondary and tertiary amines by hydrolysis or reduction of the amides, respectively. The procedure appears to be limited, however, to reactions with primary haloalkanes and dialkyl sulphates, as secondary haloalkanes are totally unreactive [6, 7]. The use of iodoalkanes should be avoided, on account of the inhibiting effect of the released iodide ion on the catalyst. Also, the A-alkylation reaction is generally susceptible to steric effects, as seen by the low yields in the A -cthylation of (V-/-butylacetamide and of A-ethylpivalamide [6]. However, the low steric demand of the formyl group permits A,A-dialkylation and it is possible to obtain, after hydrolysis in 60% ethanolic sulphuric acid, the secondary amines having one (or, in some cases, two) bulky substituent(s) [7]. 

Figure 8.2 Polyacrylamide gel formation and hydrolysis of acrylamide to acrylate. (A) Acrylamide and A,A-methylenebisacrylamide (bis) are copolymerized in a reaction catalyzed by ammonium persulfate [(NH4)2S208] and TEMED. (B) A very short stretch of cross-linked polyacrylamide is represented. Cross-linking between similar structures leads to the formation of ropelike bundles of polyacrylamide that are themselves cross-linked together forming the gel matrix. In the lower portion of (B) is shown how pendant, neutral carboxamide groups can become hydrolyzed to charged carboxyls.

This enzyme [EC 3.5.4.10] catalyzes the hydrolysis of the purine ring of IMP to produce 5-formamido-l-(5-phosphoribosyl)imidazole-4-carboxamide. 

Different alkyl or aryl iV-methoxy or iV-phenoxy carboxamides 83 were subjected to the dealkoxylation or dephenoxylation with lithium and a catalytic amount of DTBB (10%) giving, after hydrolysis, the corresponding amides 84 (Scheme 35) . ... 

A very significant mortality in Western countries is associated with cardiac arrhythmias Consequently an intensive search is underway for agents to combat this condition - particularly for compounds with an unusual mode of action A class Ic (local anesthetic-like) agent of interest in ihis context is Indecainide (50) One of several routes to this compound covered by patents begins with sodium amide mediated alkylation of 9 cyanofluorene (48) with 3 isopropylamino-1 chloropropane to give amine 49 The synthesis concludes by partial hydrolysis of the nitnle func tion to a carboxamide linkage with sulfunc acid to produce indecainide (50) [15]... 

Chiral carboxyamides derived from acid chlorides and A-chiral cA-aminoindanol can be protonated and Li Cu transmetallated to generate copper enolates which react with A-lithium derivative of A-Boc-O-tosylhydroxylamine (LiBTOC) 31 to give a-A-Boc amino carboxamides in high yields and enantiomeric excess (Scheme 38) . The chiral auxiliary can be removed by acidic hydrolysis to obtain the a-aminocarboxylic acid. 

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