Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Phosphonic acid anhydrides derivs

A dispersant that can be used in drilling fluids, spacer fluids, cement slurries, completion fluids, and mixtures of drilling fluids and cement slurries controls the rheologic properties of and enhances the filtrate control in these fluids. The dispersant consists of polymers derived from monomeric residues, including low-molecular-weight olefins that may be sulfonated or phosphonated, unsaturated dicarboxylic acids, ethylenically unsaturated anhydrides, unsaturated aliphatic monocarboxylic acids, vinyl alcohols and diols, and sulfonated or phosphonated styrene. The sulfonic acid, phosphonic acid, and carboxylic acid groups on the polymers may be present in neutralized form as alkali metal or ammonium salts [192,193]. [Pg.311]

Metal ions have been shown to catalyze the hydrolysis of phosphate esters, phosphoric and phosphonic acid halides, and various phosphoric acid anhydrides including acyl phosphates, pyrophosphate derivatives, and ATP. [Pg.32]

Radical-based dephosphorylation via a phosphonyl radical constitutes one formulation for the mechanism of C-P bond cleavage during microbial degradation of organophospho-nates.80 Frost has demonstrated that anhydrides 117 derived from phosphonic acid and thiohydroxamic acid react in a chain sequence with thiols, Bu3SnH and CC14 to give dephosphoryl-... [Pg.124]

Coppola, G.M., Hardtmann, G.E., and Pfister, O.R., Chemistry of 2//-3,l-bcn/.oxazinc-2,4(l//)-dione (isatoic anhydride). Part 2. Reactions with thiopseudoureas and carbanions, J. Org. Chem., 41, 825,1976. Kabachnik, M.L, Rossiiskaya, P.A., and Shepeleva, E.S., Esters of a-keto phosphonic acids. Part 3. Two types of carboxylic acid derivatives, Izv. Akad. Nauk SSSR, Ser. Khim., 163, 1947 Chem. Abstr, 42, 4132i, 1948. [Pg.299]

Simple derivatives of (a-hydroxyalkyl)phosphonic and analogous acids have been obtained directly by procedures analogous to those adopted for the parent compounds. Thus, O-acetates of (2,2,2-trichloro-l-hydroxyethyl)phosphonic acid esters have been prepared through the interaction of the appropriate halogenated acetaldehyde and phosphorous-acetic acid anhydrides An aromatic aldehyde and dialkyl phospho-roisocyanatidite in the presence of water or an alcohol yields analogous 0-carbamoyl derivatives of (a-hydroxybenzyl)phosphonic diesters, probably through cyclic intermedi-ates ". ... [Pg.186]

The monoaminomonophosphonic acids, either in the free state or, very often, as their diethyl esters, have been resolved by the usual techniques of repeated crystallization of appropriate salts those of L-(+)-tartaric acid (2,3-dihydroxybutanedioic acid) or its mono-or di-benzoyl derivativesor of D-(-)-mandelic acid, have been widely employed the use of di-O-benzoylated L-tartaric anhydride, which is based on the separation of diastereoisomeric amides (111), has also been employed to a limited extent. In selected cases, such as the monoaminomonophosphonocarboxylic acids or A -acylated (aminoalkyl)phosphonic acids, resolution following salt formation with organic bases has also been carried out ephedrine, quinine and both enantiomers of l-phenylethylamine have all been used. In many cases, only one enantiomer of the (aminoalkyl)phosphonic acid (or diester) has been isolated in optically pure form. Sometimes, the acidity of the substrate, and hence choice of base for resolution, can be modified by using a mono- (as opposed to di-) ester or (or even in addition to) protection of the amino group as, for example, the phthalimido, benzyloxycarbonyl (cbz) or r r -butyloxycarbonyl (boc) derivative. Resolved di- and mono-esters can be hydrolysed to the free acids under acidic conditions, and A -protection can also be removed through the customary procedures. [Pg.315]

Cyclic allq lene phosphonates, namely 2-oxo-l,3,2-dioxaphospholanes and 2-oxo-l,3,2-dioxaphosphorinanes, can be obtained through either the controlled hydrolysis of the corresponding phosphorus(III) derivative (Scheme 6.9, route A) or by a transesterification reaction between a diol and a diall l phosphonate (Scheme 6.9, route B). An alternative method has been described, based on the reaction of cyclic ethers with phosphonic acid in the presence of acetic anhydride. ... [Pg.117]

Besides the cyclic acid anhydrides, the oxaphosphorinanone oxides, which are bioisostere of acid anhydrides and inhibitors of P-lactamase [47], have also been synthesized by palladium-catalyzed C-H carbonylation of phosphonic and phos-phinic acids (Scheme 3.23) [48]. In the presence of 5mol% Pd(OAc)2, l.Sequiv. of PhI(OAc)2, and l.Sequiv. of AgOAc, benzylphosphonic and phosphinic acid derivatives could give the corresponding oxaphosphorinanone oxides in moderate to high yields by incorporation of a carbonyl group. [Pg.77]

A convenient synthesis of half-derivatives of thiophosphonic acids starts from the corresponding phosphonic dichloride, with isolation of the trimeric thiophosphonic anhydride (53)44a and subsequent reaction of this with amines and alcohols.446... [Pg.111]

A comparative analysis of the latter reagent with HOAt-derived coupling reagents showed this phosphonic anhydride to be superior when sterically hindered amino acid residues are involved in the cyclization reaction (see Vol. E22a, Section 3.9.1.2). " ... [Pg.472]

A different approach toward preparation of phosphinous and phosphonous iodides uses the reaction of iodoalkanes with either PI3 or PI5. This reaction is specific for iodoalkanes and phosphorus iodides and is not applicable to other halides. From the resultant highly reactive phosphinous and phosphonous iodides, the full range of the parent acid derivatives may be prepared (esters, other acid halides, anhydrides, amides). We will not be concerned here with these preparations of derivatives of the parent acids, topics that are considered in other reports. ... [Pg.3749]

Reactions of Phosphonic and Phosphinic Acid Derivatives.—Diphenyl-phosphinic peroxide (103) has been shown to undergo a remarkable rearrangement, either thermally or on irradiation, to give the mixed phosphinic phosphonic anhydride (104). ° Using (103) labelled with... [Pg.137]

Scheme 11 indicates the usefulness of salts derived from Wittig ylide reagents and anhydrides of perfluorocarboxylic acids in the synthesis of fluorinated alkenylphosphonic diesters (127), often together with (epoxyalkyl)phosphonic diesters (128)(Rf = CF3 or... [Pg.172]

Olefination reactions of the phosphonates (254) and (255) derived from hydantoin and 1-methylhydantoin, respectively, provide good yields of the expected C-5 unsaturated hydantoin derivatives (256), generally as mixtures of isomers. 52 Heterocyclic analogues, e.g. (257), of pulvinones and, e.g. (258), of permethylated pulvinic acids have been synthesized by Wadsworth-Emmons reactions of the phosphonates (259) and (260), themselves prepared directly from substituted maleic anhydrides. 55 The reaction of ylide (261) with aldehydes to give (262) has been used as a key... [Pg.349]

Sample of VX stored for a long time in glass container was investigated using GC/MS system. A variety of age decomposition products including O-alkyl and N,N-diisopropylamino- substituted thiophosphonic esters and acids as well as phosphonic anhydrides were identified. Diazomethane methylation was used to obtain derivatives convenient to GC process. Retention parameters and EI-MS spectra were obtained and presented in the paper. [Pg.127]

In 1991, Pattenden exploited the inherent regioselectivity of nucleophilic additions on P-methoxy maleic anhydrides to prepare gomphidic acid (30) by two different routes (Scheme 1.10) [63]. The first one involves an HWE reaction between phosphonate 80 and aryl pyruvate 81 [63b], and the second one is based on a Reformatsky-type reaction of 77 with zinc enolates derived from aryl acetate 79 [63cj. [Pg.11]


See other pages where Phosphonic acid anhydrides derivs is mentioned: [Pg.303]    [Pg.242]    [Pg.763]    [Pg.12]    [Pg.281]    [Pg.368]    [Pg.20]    [Pg.231]    [Pg.302]    [Pg.246]    [Pg.246]    [Pg.1249]    [Pg.294]    [Pg.582]    [Pg.229]    [Pg.423]    [Pg.1132]    [Pg.700]    [Pg.183]    [Pg.17]    [Pg.298]    [Pg.300]    [Pg.129]    [Pg.439]    [Pg.43]    [Pg.128]    [Pg.491]    [Pg.449]    [Pg.444]   


SEARCH



Acid anhydride derivatives

Anhydride derivatives

Phosphonic acid

Phosphonic acid derivatives

Phosphonic acid/phosphonate

Phosphonic acids acidity

Phosphonous acid

Phosphonous acid derivs

© 2024 chempedia.info