Anhydrides amides

Thiazolecarboxylic acid hydrazides are prepared by the same general methods used to prepare amides, that is, by treating acids, esters, amides, anhydrides, or acid halides with hydrazine or substitued hydrazines. For example, see Scheme 21 (92). The dihydrazides are obtained in the same way (88). With diethyl 2-chloro-4,5-thiazoledicarboxylate this reaction gives the mono hydr azide monoester of 2-hydrazine-4,5-... 

Carboxylic acid hydiazides are prepared from aqueous hydrazine and tfie carboxylic acid, ester, amide, anhydride, or halide. The reaction usually goes poody with the free acid. Esters are generally satisfactory. Acyl halides are particularly reactive, even at room temperature, and form the diacyl derivatives (22), which easily undergo thermal dehydration to 1,3,4-oxadiazoles (23). Diesters give dihydtazides (24) and polyesters such as polyacrylates yield a polyhydrazide (25). The chemistry of carboxyhc hydrazides has been reviewed (83,84). 

As with carboxylic acids obtained by palladium hydroxycarbonylation, their derivatives esters, amides, anhydrides and acyl halides are synthesized from alkenes, CO and HX (X = OR, NR2 etc.). The Pd-catalyzed methoxycarbonylation is one of the most studied reactions among this type of catalyzed carbonylations and has been reviewed and included in reports of homogeneous catalysis.625, 26 The methoxycarbonylation has been applied to many different substrates to obtain intermediates in organic syntheses as well as specific products. For instance, the reaction has been applied for methoxycarbonylation of alkynes666 Highly efficient homogeneous Pd cationic catalysts have been reported and the methoxycarbonylation of alkynes has been used to develop economically attractive and environmentally benign process for the production of methyl... 

These reaction conditions also permit the chemoselective quantitative reduction of benzaldehyde to benzyl alcohol without any concomitant reduction of either acetophenone or 3,3-dimethylbutan-2-one present in the same reaction mixture.83 Additionally, this useful method permits the reduction of aldehyde functions in polyfunctional compounds without affecting amide, anhydride, eth-ylenic, bromo, chloro, or nitro groups.79,80,319... 

Carboxylic acids and their derivatives like esters, amides, anhydrides, and acyl halides are formally synthesized from olefins, carbon monoxide, and compounds represented by Nu-H such as H2O, ROH, RNH2, RCOOH (Equations (4) and (5)). Alkynes also react under similar conditions to afford the corresponding unsaturated carboxylic acid derivatives. These reactions have been named hydrocarboxylation, hydroalkoxycarbonylation, and hydroaminocarbonylation. 

Volume 10 is devoted to formation and solvolysis of esters and related reactions, with discussion of the effect of neighbouring groups and biological implications, e.g. enzyme action, where appropriate. The first chapter deals mainly with esters of the inorganic acids of phosphorus and sulphur, Chapter 2 with the formation and solvolysis of esters of organic acids and the final chapter with the solvolysis of related derivatives of carboxylic acids, e.g. halides, amides, anhydrides, cyanides, carbamic acid derivatives. 

In between, there are carbonyl compounds ranging from aldehydes and ketones to carboxylic acids and their derivatives (esters, amides, anhydrides, and acyl... 

Finally, reacting an N,N-disubstituted amide anhydride with dilute aqueous acid produces a carboxylic acid. 

DMAP 29 is a powerful catalytic activating agent for the reaction of nucleophiles with esters, amides, anhydrides or carboxylic chlorides. It is much more reactive than pyridine (pKa = 5.23) because of the enhanced basicity (pKa = 9.70) and nucleophilicity.15... 

Early experiments in the preparation of alkanolamides were begun by Kritchevs-ky (24, 25). It involves condensation reactions of fatty acids, triglycerides, esters, amides, anhydrides, and halides with an alkanolamine. The reaction was carried out at 100-300°C at atmospheric pressure. An important improvement was made by... 

This chapter is concerned with the cathodic reduction of carboxylic acids and their derivatives, that is, esters, amides, anhydrides, acyl halides, hydrazides, nitriles, and corresponding thio derivatives. Cyclic derivatives of substituted carboxylic and polycarboxylic acids, such as lactones, lactams, imides, and anhydrides, are also included. Only those transformations in which the functional group itself is involved are discussed. Reductive coupling of carboxylic acids and derivatives is covered in Chapter 22, and there is some overlap with reduction of heterocycles in Chapter 18. 

Similar experiments have indicated the reversible formation of tetrahedral intermediates in hydrolysis of other esters, amides, anhydrides, and acid chlorides, and are the basis of the general mechanism we have shown for nucleophilic acyl substitution. 

A very large number of cyclopropylamines have been converted to different A-cyclopropyl compounds by using general methods for amine transformations. This transformation will not be covered extensively here. In general, the yields vary from excellent to mediocre. Acylation reactions have been reported to take place by employing reagents such as acid chlorides in the presence of a amides,anhydrides in the absence s ... 

The major part of the phosphorus-containing insecticides cannot be considered as organophosphorus compounds in the strict sense because they do not contain a P—C bond. These compounds are esters, amides, anhydrides and fluorides of phosphoric, phosphorothioic and phosphorodithioic acids. Most of them can be classified in one of the types shown in Table 1.2. 

Carboxylic acids can be activated in several ways, such as conversion to the corresponding acid chlorides, imidazole amides, anhydrides, or by using coupling reagents such as DCC. We chose pivaloyl chloride for initial development, because the hindrance of the pivaloyl group should favor the desired selectivity with the corresponding mixed anhydride 11. 

In addition to ion formation the sulfonic acid group may form other derivatives, such as sulfonyl chlorides, amides, anhydrides, etc. The literature referring to these derivatives is much less extensive and their importance is rather limited. These will be referred to in Section IV. 

PA-6 (70) / EP (0-30) / EP-g-MA (0-30) internal mixer at 240°C / SEM / effects of adding phthahc anhydride to consume amine end-groups / model reactions to assess roles of amine- vs. amide-anhydride reactions Marechal et al., 1995... 

In this process, the ring strain of the monomer is relieved when the ring is broken into a linear structure, covalently and sequentially linked in the presence of a catalyst (initiator). There is no loss or gain of any atom or group. The monomer rings have ether, amide, anhydride, sulphide or other linkages. 

Marechal, P., Coppens, G., Legras, R., and De-Koninck, J. M. 1995. Amine/anhydride reaction versus amide/anhydride reaction in polyamide/anhydride carriers. Journal of Polymer Science, Part A Polymer Chemistry 33 757-766. 

Epoxy adhesives are cured by amines, amides, anhydrides, polysulfides, and amino and... 

EP-g-MA (0-30) adding phthalic anhydride to consume amine end-groups/model reactions to assess roles of amine- vs. amide-anhydride reactions 1995... 

Carbonyl addition-elimination n. The single most important type of reaction mechanism which has been applied to the preparation of step-growth polymers is the addition-elimination reaction of the carbonyl double bond of carboxylic acids and carboxylic acid derivatives included in this general type of reaction are esterification amidation and anhydride formation from carboxylic acids, esters, amides, anhydrides and acid halides. 

CARBOXYLIC ACIDS ARE another class of organic compounds containing the carbonyl group. Their occurrence in nature is widespread, and they are important components of foodstuffs such as vinegar, butter, and vegetable oils. The most important chemical property of carboxylic acids is their acidity. Furthermore, carboxylic acids form numerous important derivatives, including esters, amides, anhydrides, and acid halides. In this chapter, we study carboxylic acids themselves in Chapters 14 and 15, we study their derivatives. 

General methods for the synthesis of poly(amide-anhydrides) and poly(amide-esters) based on naturally occurring amino acids were described (Domb et at, 1990). The polymers were synthesized from dicarboxylic acids prepared by amidation of the amino group of an amino acid with a cyclic anhydride, or by the amide coupling of two amino acids with a diacid chloride. Low molecular weight polymers from methylene bis(p-carboxybenzamide) were symthesized by melt condensation (Hartmann et al, 1989). A series of amido containing polyanhydrides based on p-aminobenzoic acid were sy nthesized by melt condensation. The polymers melted at 58 to 177°C and had a molecular weight of 2500 to 12400. 

Add halides are important intermediates and they are used extensively for the conversion of carboxylic adds into other derivatives. For example, add halides can be used to prepare (in addition to amides) anhydrides, esters, aldehydes, and ketones. Add halides readily undergo reaction with water (hydrolysis) to form the corresponding carboxylic add. For this reason the reaction system must be protected from atmospheric moisture when add halides are formed and/or used. 

Draw structural formulas for the products formed by hydrolysis at pH 7.4 (the pH of blood plasma) of all ester, thioester, amide, anhydride, and glycoside groups in acetyl... 

B-l-alkynyl-9-BBN compounds are exceptionally mild reagents and are essentially inert at 25 °C toward alkyl halides, acid chlorides, amides, anhydrides, esters, nitriles, acetals, and ketals. 

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