Benzohydroxamate

The 3-o-ch orophenvl-5-methvlisoxa2ole4-carboxylic acid, from which the acid chloride was prepared, was obtained by hydrolysis of the ester product of the reaction between o-chloro-benzohydroxamic chlorideand ethyl acetoacetate in methanolic sodium methoxide. Reaction with thionyl chloride gave the starting material. 

The excess acidity method has been used to show that some reactions do have pure A2 mechanisms, for instance the hydrolysis of some benzohydroxamic acids,126,211 the hydrolysis of sultams,212 and the oxidation of lactic acid in... 

The pentacoordinate silicon compounds 81, 8,54 82,54 83,54 and 8455 are spirocyclic zwitterionic A5S7-silicates with an Si04C skeleton. The chiral zwitterions contain two diolato(2—) ligands that formally derive from aceto-hydroximic acid and benzohydroximic acid (tautomers of acetohydroxamic acid and benzohydroxamic acid). 

The pentacoordinate silicon compounds 94,23 95,23 96-98,60 99,60,61100,61,62 101-103,60 104,61,62 105,62 106,62 and 10761,63 are monocyclic zwitterionic A5S7-silicates with an Si02FC2 skeleton. The chiral zwitterions each contain one bidentate diolato(2-) ligand that formally derives from 1,2-dihydroxy-benzene, salicylic acid, glycolic acid, oxalic acid, benzohydroximic acid (tautomer of benzohydroxamic acid), 2-methyllactic acid, or (S)-mande-lic acid. 

Related benzohydroxamic acids such as (120), with similar properties, were reported from Roussel [295]. Additional cinnamohydroxamic acids, re-... 

The neutral alkali metal salts of benzohydroxamic acids have been found to undergo an unprecedented rearrangement to A(,A( -diarylureas. 2 side reaction, producing /9-alanine derivatives by way of a Lossen rearrangement, has been observed to accompany the hydrolysis of alkyl succinimidyl carbonates in basic aqueous buffers (see Scheme 97). The development of a modified Lossen rearrangement, whereby... 

NN -Ethylenediaminediacetate-NN -diacethydroxamic acid Tetraethylenepentamine-hepta-acetate Monoethanolamine Benzohydroxamic acid Copper(li)... 

For example, the complexes [Mn (N)(CN)4] and [Mn (L)3] (L = benzohydroxamic acid) in CH3CN solutions show irreversible anodic responses in their cyclic voltammograms suggesting Mn and Mn complexes are formed. ... 

What about the isomers of the hydroxamic acids, the 0-acyl derivatives of hydroxy-lamine Having mentioned early in this study that N-methylhydroxylamine is more stable than its O-isomer, we are thus intrigued by the finding that iV-benzoylhydroxylamine (benzohydroxamic acid), or at least its A -f-butyl derivative, is less stable than its corresponding O-benzoyl isomer as shown by the thermal isomerization of the former to the latter, equation 55. 

Hi8C1JNU3 4-Butoxy-A -(4-chlorophenyl) benzohydroxamic acid Ebciraction-photometric Nb, Ta, Ti 3... 

C19H15N302 N-Phenyl-4-(phenylazo) benzohydroxamic acid Color reaction V 3... 

Some interesting solvent effects have been observed as a function of medium change in the acetonitrile-water system. Benzohydroxamate (BHA", pKa = 8.8) has been shown to be more reactive than its reference nucleophile, 3-chlorophenoxide (3-CIC5H4O", pKa = 9.02) toward 4-nitrophenyl acetate (PNPA) as shown in Figure 3 BHA" is ca 160-fold more reactive than S-ClCeFLtO" in pure water but the reactivity ratio,... 

A-Acetoxy-A-butoxybenzamides (101) react in aqueous acetonitrile by an autocat-alytic process. In the presence of added mineral acid, they undergo acid-catalysed AaiI solvolysis forming A-aroyl-A-butoxynitrenium ions (102), which are trapped by water. The hydroxamic acid product (103) reacted under the conditions to give a range of products that included, n-butanol, butanal, benzoic acids, benzohydroxamic acids and butyl benzoates (Scheme 18)92.93,95, ns, i56 ... 

The crystal structure of (ethylenediamine)zinc benzohydroxamate hydrate has been reported.188 The two benzohydroxamate ions and an ethylenediamine form a distorted octahedron about the zinc. The asymmetric unit also contains a water molecule and a benzohydroxamic acid molecule. 

BenzoKydroxamic Acid and Derivatives Benzohydroxamic Acid(called Benzhydroxamsaure,... 

Hydroxamic acid exists in two tautomeric forms, (1) and (2), and such keto-enol tautomerism provides a number of sites for coordination and chelation. The keto form (1) predominates in acid media and the enol form (2) in alkaline media 25 this has been corroborated by the extraction of vanadium benzohydroxamic acid complexes in organic solvents.26... 

Kundu and Bhattacharya14 have isolated dioxouranium complexes of benzohydroxamic acid with the compositions M[U02(C7H602N)3] [where M = Li, Na, K, Cs, Tl, N4, pyH+ (pyridinium) or agH+ (aminoguanidinium)] and M [U02(C7H602N)3]2 [where M = enH2+ (ethylene-diammonium)]. All the complexes, with the exception of the sodium compound, are insoluble in common organic solvents but are soluble in DMSO and DMF. The complexes have been characterized on the basis of electronic, IR and molar conductance data in DMF. Their fairly stable character is indicated by thermogravimetric analysis and the stability order is NH4+ < Tl+ < Cs+ < Li+ w Na+ agH+ < K+ pyH+ < enHl+. 

Benzohydroxamic acid dioxouranium complexes, 507 metal complexes, 506, 507 as metal precipitant, 506 Benzohydroxamic acid, iV-methyl-metal complexes, 506 Benzohydroxamic acid, N-phenyl-metal complexes, 507 reactions with carboxylic acids, 507 as metal precipitant, 506 titanium complexes, 506 Benzohydroxamic acid, A -(o-tolyl)-as metal precipitant, 506 Benzohydroxamic acid, N-wi-tolyl-p-methoxy-metal complexes, 506 Benzoic acid, dihydroxy-beryllium(II) complexes, 481 Benzoic acid, o-mercapto-esters... 

Hydroxamic acids have been the subject of six papers 43 90 94 Earlier the operation of the a-effect in the reaction of p-nitrophcnyl acetate with benzohydroxamates in aqueous MeCN was discussed.43 The conformational behaviour of series of mono- (105) and di-hydroxamic acids (106) in MeOH, DMSO, and chloroform and in the solid state has been examined witii IR and NMR spectroscopy.90 X-ray crystal structure determinations of (105 X = Me, R = Me) and die monohydrate of glutarodihydroxamic acid (106 n = 3, R = H) together widi ab initio MO calculations for several hydrated and non-hydrated acids have been performed. The cis-Z conformation of the hydroxamate groups is preferentially stabilized by H-bonding witii water. 

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