Acid chloride esters from

Alternate Preparations Of a-Keto Esters From Acid Chlorides," Katritzky. A.R. Wang, Z. Wells, A.P. Org. Prep. Proceed. Int., 1995, 21, 457... 

The alkyl group of the salt of the alkylsulphuric acid can also be made available for esterification if the temperature is raised sufficiently. The formation of esters from acid chlorides or anhydrides need only be recalled here. This method also has practical importance. 

Dimethylaminoethane-2-ol (20) is a compound that, by virtue of its nucleophilic center (Me2NH+C2H40), is employed to convert protected segments bound to supports as benzyl esters into acids by transesterification into dimethylaminoethyl esters [C(=0)0C2H4NMe2] that are hydrolyzable by a dimethylformamide-water (1 1) mixture. Compound 20 readily forms esters from acid chlorides. The hydrolysis and esterification are facilitated by anchimeric assistance by the adjacent nitrogen atom (see Section 2.10). The amino alcohol also reacts with dichloromethane. 

Esters from acid chlorides and alkyl halides... 

The formation of esters from acid chlorides and anhydrides according to the following equation has been discussed ... 

In Chapter 12 pyridine was often used as a catalyst in carbonyl substitution reactions. It can act in two ways. In making esters from acid chlorides or anhydrides pyridine can act as a nucleophile as well as a convenient solvent. It is a better nucleophile than the alcohol and this nucleophilic catalysis is discussed in Chapter 12 (p. 282). But nonnucleophilic bases also catalyse these reactions. For example, acetate ion catalyses ester formation from acetic anhydride and alcohols. 

L4 Fmoc Amino Acid Esters from Acid Chlorides... 

This reversibility is a disadvantage in the preparation of an ester directly from an acid the preference for the acid chloride route is due to the fact that both steps—preparation of acid chloride from acid, and preparation of ester from acid chloride—are essentially irreversible and go to completion. 

In the synthesis of a-hydroxy /3-keto esters from acid chlorides and methyl phenylglyoxylate the sensitivity of acid chlorides requires maintenance of an anhydrous condition and the presence of pyridine to capture HCl. 

It has been noticed that in some reactions the part played by alcohols corresponds to the part played by the acid, HA for instance, in the formation of esters from acid chlorides and alcohols, in the type reaction... 

Esters from acid chlorides, phenols or I cyclohexanols in pyridine or reagents (viii)... 

Polymeric amines can be proton acceptors, acyl transfer agents, or ligands for metal ions. The 2- and 4-isomers of poly(vinylpyridine) (11) and (12) and the weakly basic ion exchange resins, p-dimethylaminomethylated PS (2) and poly(2-dimethylaminoethyl acrylate), are commercial. The ion exchange resins are catalysts for aldol condensations, Knoevenagel condensations, Perkin reactions, cyanohydrin formation and redistributions of chlorosilanes. " The poly(vinylpyridine)s have been used in stoichiometric amounts for preparation of esters from acid chlorides and alcohols, and for preparation of trimethylsilyl ethers and trimethylsilylamines from chlorotrimethylsilane and alcohols or amines. Polymer-suppored DBU (l,8-diazabicyclo[5.4.0]undec-7-ene) (52) in stoichiometric amounts promotes dehydrohalogenation of alkyl bromides and esterification of carboxylic acids with alkyl halides. The protonated tertiary amine resins are converted to free base form by treatment with aqueous sodium hydroxide. 

The most general methods for the syntheses of 1,2-difunctional molecules are based on the oxidation of carbon-carbon multiple bonds (p. 117) and the opening of oxiranes by hetero atoms (p. 123fl.). There exist, however, also a few useful reactions in which an a - and a d -synthon or two r -synthons are combined. The classical polar reaction is the addition of cyanide anion to carbonyl groups, which leads to a-hydroxynitriles (cyanohydrins). It is used, for example, in Strecker s synthesis of amino acids and in the homologization of monosaccharides. The ff-hydroxy group of a nitrile can be easily substituted by various nucleophiles, the nitrile can be solvolyzed or reduced. Therefore a large variety of terminal difunctional molecules with one additional carbon atom can be made. Equally versatile are a-methylsulfinyl ketones (H.G. Hauthal, 1971 T. Durst, 1979 O. DeLucchi, 1991), which are available from acid chlorides or esters and the dimsyl anion. Carbanions of these compounds can also be used for the synthesis of 1,4-dicarbonyl compounds (p. 65f.). 

Ahyl alcohol undergoes reactions typical of saturated, aUphatic alcohols. Ahyl compounds derived from ahyl alcohol and used industriahy, are widely manufactured by these reactions. For example, reactions of ahyl alcohol with acid anhydrides, esters, and acid chlorides yield ahyl esters, such as diahyl phthalates and ahyl methacrylate reaction with chloroformate yields carbonates, such as diethylene glycol bis(ahyl carbonate) addition of ahyl alcohol to epoxy groups yields products used to produce ahyl glycidyl ether (33,34). 

These processes have supplanted the condensation reaction of ethanol, carbon monoxide, and acetylene as the principal method of generating ethyl acrylate [140-88-5] (333). Acidic catalysts, particularly sulfuric acid (334—338), are generally effective in increasing the rates of the esterification reactions. Care is taken to avoid excessive polymerisation losses of both acryflc acid and the esters, which are accentuated by the presence of strong acid catalysts. A synthesis for acryflc esters from vinyl chloride (339) has also been examined. 

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. 

Pyridazinecarbohydrazides are prepared in the normal way from an ester or acid chloride and hydrazine or a substituted hydrazine, generally in good yields. Pyridazines with two ortho alkoxycarbonyl groups give cyclic hydrazides with hydrazine, which are pyridazinopyridazines. 

One year later, Tietze and co-workers (97BMC1303) presented a general and straightforward method for the synthesis of diverse polymer-bound -keto esters starting from acid chlorides and Meldrum s acid. One such resin-bound y3-keto ester, 43, was treated with hydrazine hydrate in THF to afford resin-ffee N-2-unsubstituted pyrazolone 44 in 84% yield (Scheme 13). In the same paper, the synthesis of a large number of 4,5-disubstituted 2-phenyl-2,4-dihydro-37/-pyrazol-3-ones was reported. 

One of the few nonnitrogenous compounds to show spasmolytic activity is a rather simple chromone. Acylation of the phenolic ketone, 31, with the half ester-half acid chloride from oxalic... 

Acid anhydride, amides from, 807 eleclrostatic potential map of, 791 esters from, 807 from acid chlorides, 806 from carboxylic acids, 795 1R spectroscopy of, 822-823 naming, 786... 

Answer Friedel-Crafts disconnection requires the half ester, half acid-chloride (16) which we could make from Daleic anhydride (17) as on p T 39. An easier solution is to use the anhydride in the Friedel-Crafts reaction. The two methyl groups cooperate to activate the right position and the yield is excellent,... 

Cote, G. Jakubiak, A. Bauer, D. Szymanowski, J. Mokili, B. Poitrenaud, C. Modeling of extraction equilibrium for copper(II) extraction bypyridinecarboxylic acid esters from concentrated chloride solutions at constant water activity and constant total concentration of ionic or molecular species dissolved in the aqueous solution. Solvent Extr. 

Organometallic compounds or carbanions undergo a number of reactions in which the carbanion or carbanion-like moiety of the organometallic compound acts as a nucleophilic displacing agent. Examples are the formation of hydrocarbons from alkyl halides, alkyl halides from halogens, and ketones from acid chlorides or esters. The latter two reactions are closely related to the base-catalyzed condensations and are perhaps additions as well as displacement reactions. Related addition reactions are the carbonation of organometallic compounds and the addition to ketones or aldehydes. 

The required epoxy esters are obtained by reaction of the free acid (0.96 mmol) with 3,4-epoxy-3-methylbutanol (1.1 mmol), DCC (1.1 mmol), and DMAP (0.048 mmol) in CH2C12/DMF (9 1, 10 mL, 1 h at 0 °C and 2 h at r. t.). Alternatively, they can be synthesized from acid chlorides using 3-methyl-3-butenol and triethylamine (1 1 2 ratio CH2C12, 0°C), followed by epoxidation with m-chloroperbenzoic acid (1.2 equivalents, CH2C12, 0°C). 

Phosgene is a colorless gas at ambient temperature and pressure. Its odor has been described as similar to new-mown hay. Phosgene is manufactured from a reaction of carbon monoxide and chlorine gas in the presence of activated charcoal. The production of dyestuffs, isocyanates, carbonic acid esters (polycarbonates), acid chlorides, insecticides, and pharmaceutical chemicals requires phosgene. Manufacture of phosgene is approximately 1 million tons per year (y) in the United States, and more than 10,000 workers are involved in its manufacture and use. Manufacture of phosgene in the United States is... 

ALDEHYDES BY OXIDATION OF TERMINAL OLEFINS WITH CHROMYL CHLORIDE 2,4,4-TRIMETHYL-PENTANAL, 51, 4 ALDEHYDES FROM ACID CHLORIDES BY MODIFIED ROSENMUND REDUCTION 3,4,5—TRIMETHOXYBENZ-ALDEHYDE, 51, 8 ALDEHYDES FROM ACID CHLORIDES BY REDUCTION OF ESTER MESYLATES WITH SODIUM BOROHY-DRIDE CYCLOBUTANECARBOXAL-DEHYDE, 51, 11... 

The reaction of Curtius, which is especially to be preferred in the case of the higher members on account of the favourable solubilities of the intermediate products, involves as its first stage the preparation of the hydrazide from an ester (or acid chloride). The hydrazide is then converted, usually very readily, by the action of nitrous acid into the azide. In many cases it is more convenient to prepare the azide by treating an acid chloride with sodium azide previously activated with hydrazine hydrate.1 Azides easily undergo thermal decomposition, the two azo nitrogen atoms being eliminated as elementary nitrogen. In this way, however, the same radicle is formed as was invoked above to explain the Hofmann reaction ... 

Amines also react with esters by a method similar to the reaction of an acid chloride with an cimine (which was described in the previous section, From acid chlorides ). Figure 12-28 illustrates the formation of benzamide by this type of reaction, using ammonia and methyl benzoate. Again, the mechanism is similar to the reaction of an acid chloride with an amine (Figure 12-26). 

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