Chloride Acids, aliphatic

The choice of type of derivative should be based on whether the chloride or anhydride is aliphatic or aromatic, because this factoi largely determines the reactivity. Aliphatic acid chlorides are best converted into their anilides, as in 4 above aromatic acid chloride may be similarly converted into their anilides, or they may be converted into their amides by shaking with an excess of ammonia (p, 120). (M.ps., pp. 544-545.) Aliphatic acid anhydrides should be converted into their crystalline anilides, but aromatic acid anhydrides arc best hydrolysed to the acid, which can then be converted into one of the standard derivatives (p. 349). 

The above simple experiments illustrate the more important properties of aliphatic acid chlorides. For characterisation, the general procedure is to hydrolyse the acid chloride by warming with dilute alkali solution, neutralise the resulting solution with dilute hydrochloric acid (phenol-phthalein), and evaporate to dryness on a water bath. The mixture of the sodium salt of the acid and sodium chloride thus obtained may be employed for the preparation of solid esters as detailed under Aliphatic Acids, Section 111,85. The anilide or p-toluidide may be prepared directly from the acid chloride (see (iii) above and Section III,85,i). 

The physical properties of a number of aliphatic acid chlorides are collected in Table 111,88. 

Acyl halides are intermediates of the carbonylations of alkenes and organic-halides. Decarbonylation of acyl halides as a reversible process of the carbo-nylation is possible with Pd catalyst. The decarbonylation of aliphatic acid chlorides proceeds with Pd(0) catalyst, such as Pd on carbon or PdC, at around 200 °C[109,753]. The product is a mixture of isomeric internal alkenes. For example, when decanoyl chloride is heated with PdCF at 200 C in a distillation flask, rapid evolution of CO and HCl stops after I h, during which time a mixture of nonene isomers was distilled off in a high yield. The decarbonylation of phenylpropionyl chloride (883) affords styrene (53%). In addition, l,5-diphenyl-l-penten-3-one (884) is obtained as a byproduct (10%). formed by the insertion of styrene into the acyl chloride. Formation of the latter supports the formation of acylpalladium species as an intermediate of the decarbonylation. Decarbonylation of the benzoyl chloride 885 can be carried out in good yields at 360 with Pd on carbon as a catalyst, yielding the aryl chloride 886[754]. 

The acylation of enamino ketones can take place on oxygen or on carbon. While reaction at nitrogen is a possibility, the N-acylated products are themselves acylating agents, and further reaction normally takes place. The first reported acylation of enamino ketones (72) was that of 129, prepared by acylation of the enamine (113), which was shown to have undergone O acylation because on mild hydrolysis the enol ester (130) could be isolated. A similar reaction took place with other aliphatic acid chlorides (80) and with dibasic acid chlorides [e.g., with succinyl chloride to give 118 above]. 

The reaction doe.s not involve dehydrogenation and may also be applied (with low yield) to aliphatic acid chlorides. The reaction with aryl isocj anates proceeds analogously to the reaction with ketenes leading through a-ketoiminoketenes to atylimino-4-pyrones, identical to those obtained by Bardone-Gaudemar and described at the end of Section II,B,2,a (see Scheme 6). 

The sulfonylated and acylated PPO presents solubility characteristics which are completely different from those of the parent PPO. Table V presents the solubility of some modified structures compared to those of unmodified PPO. It is very important to note that, after sulfonylation, most of the polymers become soluble in dipolar aprotic solvents like dimethyl sulfoxide (DMSO), N,N— dimethylformamide (DMF) and N,N-dimethylacetamide (DMAC). At the same time it is interesting to mention that, while PPO crystallizes from methylene chloride solution, all the sulfonylated polymers do not crystallize and form indefinitely stable solutions in methylene chloride. Only some of the acetylated polymers become soluble in DMF and DMAC, and none are soluble in DMSO. The polymers acetylated with aliphatic acid chlorides such as propionyl chloride are also soluble in acetone. 

Oleoyl chloride has been prepared by treatment of oleic acid with thionyl chloride,3 phosphorus trichloride or pentachloride, and oxalyl chloride.4 The highest yield (86%) reported was secured by use of oxalyl chloride in carbon tetrachloride, but the more economical phosphorus trichloride gave a yield of 60%. The standard procedures for obtaining aliphatic acid chlorides have been described many times without inclusion of details other than physical properties. Only references to the procedures useful in the laboratory are given. 

The phase-transfer catalysed reaction of alkyl halides with potassium carbonate in dimethylacetamide, or a potassium carbonate/potassium hydrogen carbonate mixture in toluene, provides an excellent route to dialkyl carbonates without recourse to the use of phosgene [55, 56], An analogous reaction of acid chlorides with sodium hydrogen carbonate in benzene, or acetonitrile, produces anhydrides (3.3.29.B, >80%), although there is a tendency in acetonitrile for aliphatic acid chlorides to hydrolyse yielding the acids [57]. 

We have described (88TL4855) a simple synthesis of pyridin-2-ones by a two-step annulation of 2 with aliphatic acid chlorides (Scheme 27). The acylation of aminoazadienes 2 in pyridine furnished 4-amidoyl-l-azabutadienes 107 in high yields (85JOC802) lithium diisopropylamide-catalyzed aldol-type cyclization of 107 afforded pyridin-2-ones 108 in 83-94% yield. Extension of this reaction to methanesulfonyl chloride permitted preparation of open-chain derivatives 109 in 88-90% yield, which in turn cyclized in the presence of lithium diisopropylamide to 2//-l,2-thiazines 110 in 82-92% yield (89TL4705). Earlier work by the Komatsu-Ohshiro group showed that the reaction of simple 1-azadienes... 

The catalyst system consists of (PhCN)2PdCl2 and a phosphine or amine cocatalyst. The cocatalyst is necessary for the reaction, except in the case of the most reactive acid chlorides, such as trimellitic anhydride acid chloride or m-nitrobenzoyl chloride. Although both phosphine and amine cocatalysts are effective in the system, greater reaction rates are observed with phosphines. The reaction does not proceed in the same manner for aliphatic acid chlorides. 

The method described here, discovered by Newman and Beal,6 employs triethylamine (1 equivalent) to react with the hydrogen chloride thus only one equivalent of diazomethane is necessary. This modification is restricted to the preparation of aromatic diazoketones-aliphatic acid chlorides give a mixture of products. ... 

Reduction of aliphatic acid chlorides follows a roughly similar course78. That is, tetrameric products similar to 54 are the major products, together with small amounts of the corresponding aldehyde. The latter has been suggested to be formed from both acyl radical... 

Most reactions in two-phase systems occur in a liquid phase following the transfer of a reactant across an interface these are commonly known as extractive reactions. If the transfer is facilitated by a catalyst, it is known as phase-transfer catalysis [2]. Unusually, reactions may actually occur at an interface (interfacial reactions) examples include solvolysis and nucleophilic substitution reactions of aliphatic acid chlorides [3 ] and the extraction of cupric ion from aqueous solution using oxime ligands insoluble in water [4], see Section 5.2.1.3(ii). 

The MEMED technique has been used to study the hydrolysis of aliphatic acid chlorides in a water/l,2-dichloroethane (DCE) solvent system [3]. It was shown unambiguously that the reaction proceeds via an interfacial process and shows saturation kinetics as the concentration of acid chloride in the DCE increases the data were well fitted to a model based on a pre-equilibrium involving Langmuir adsorption at the interface. First-order rate constants for interfacial solvolysis of CH3(CH2) COCl were 300 150(n = 2), 200 100(n = 3) and 120 60 s-1( = 8). 

Such delocalization is not possible in cyclohexanecarbonyl chloride or any other aliphatic acid chloride. For this reason, aryl acid chlorides are usually less reactive toward nucleophiles than are aliphatic acid chlorides. 

As the first step, we have tried to acylate wood in a triflu-oroacetic anhydride (TFAA)-higher aliphatic acid system at 30 or 50 °C (TFAA method) and in a higher aliphatic acid chloride-pyri-dine-DMF system at 100 °C (Chloride method) (15). Both the methods resulted in thermally meltable products. An example of the thermomechanical diagram for the products is shown in Fig. 11. In this figure, the diagram for a lauroylated wood sample prepared by the TFAA method is compared with that for untrated wood. The lauroylated wood shows thermal behavior with a sharp drop caused by complete flow of the sample at 195 °C. 

Methyl-1,2-dihydroisoquinoline has been reacted8,66 with a variety of acid chlorides (Table III) the expected vinylogous amides (64) were isolated in most cases. 2-Benzyl-l,2-dihydroisoquinoline behaves similarly. The acylation reaction fails with simple aliphatic acid chlorides. Sometimes, the reaction of the enamine with the acid in the presence of dicyclohexylcarbodimide succeeds. The 1,2-dihydro-isoquinoline (65) also reacts with ethoxalyl chloride to yield 66.86... 

In this context, zirconium chemistry could open up new prospects for developing deoxygenative approaches to cyclopropanes. The Zr-assisted variant of the Kulinkovich reaction has been reported (Scheme 4, Eq. 1) [10]. Cyclopropanols were also formed, as by-products in addition to homoallylic alcohols, from aliphatic acid chlorides (Eq. 2) [ 10]. The conversion of acid chlorides (and also esters in several cases) into the corresponding homoallylic alcohols... 

The methylene chloride-water method has demonstrated a wide range of utility and aromatic, aliphatic, cyclic, and diacid chlorides have been used to give the appropriate Reissert compound. It is of interest to note that despite the presence of water in the system it can be used successfully with even aliphatic acid chlorides. 

Aliphatic acid chlorides react with H2S3 in the presence of ZnCb at 20 °C (no solvent) according to eqnation (66). ... 

Acid Chlorides. Phenyl dichloroarsine, when treated with the aliphatic acid chlorides, e.g., acetyl chloride, in carbon disulphide solution and in presence of aluminium chloride, forms acetophenone and arsenic trichloride ... 

Aromatic acid chlorides (ArCOCl) are considerably less reactive than the aliphatic acid chlorides. With cold water, for example, acetyl chloride reacts almost explosively, whereas Benzoyl chloride reacts only very slowly. The reaction of aromatic acid chlorides with an alcohol or a phenol is often carried out using the Schotten-Baumaiin technique the acid chloride is added in portions (followed by vigorous shaking) to a mixture of the hydroxy compound and a base, usually aqueous sodium hydroxide or pyridine (an organic base, Sec. 31.11). Although the function of the base is not clear, it seems not only to neutralize the hydrogen chloride that would otherwise be liberated, but also tp catalyze the reaction. 

Other aromatic and aliphatic acid chlorides give good to excellent yields of the desired ketones using this procedure. Hindered or a. -unsaturated acid chlorides also function effectively, the latter forms a, -unsaturated ketones without competing conjugate addition (equations 75 and 76). 

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