A Saponification Reaction

Esters can be hydrolysed in aqueous acid (see Section 9.4.2) or base. In basic solution, this is known as a saponification reaction, and this... 

What is saponification Write a general equation for the saponification of a triglyceride. What are the ionic products of a saponification reaction more commonly called ... 

The reaction of azido compounds and acid produces hydragoic acid. The reactions of hydragoic acid and other ions generate explosive chemical compounds with high risk. The reaction of azido chemicals with base is a saponification reaction. This reaction decomposes the chemicals but it is not dangerous. 

Esters (RCO2R) can be hydrolysed in aqueous acid (see Section 9.4.2) or base. In basic solution, this is known as a saponification reaction and this has an important application in the manufacture of soaps from vegetable oils or fats. Whereas acid hydrolysis is reversible, base hydrolysis is irreversible due to the formation of the resonance-stabilised carboxylate ion. 

What is the product of a malonic acid synthesis if the final step uses aqueous hydroxide ion in a saponification reaction followed by careful neutralization with HCl rather than an acid-catalyzed hydrolysis reaction ... 

Many industrial processes involve a chemical reaction between two Hquid phases, for example nitration (qv), sulfonation (see Sulfonation and sulfation), alkylation (qv), and saponification. These processes are not always considered to be extractions because the main objective is a new chemical product, rather than separation (30). However these processes have many features in common with extraction, for example the need to maintain a high interfacial area with the aid of agitation and the importance of efficient phase separation after the reaction is completed. 

Chemically Modified Waxes. Hydrocarbon waxes of the microcrystaHine, polyethylene, and polymethylene classes are chemically modified to meet specific market needs. In the vast majority of cases, the first step is air oxidation of the wax with or without catalysts (11). The product has an acid number usuaHy no higher than 30 and a saponification number usuaHy no lower than 25. An alternative step is the reaction of the wax with a polycarboxyHc acid, eg, maleic, at high temperature (12). Through its carboxyl groups, the oxidised wax can be further modified in such reactions as saponification or esterification. Oxidised wax is easily emulsified in water through the use of surfactants or simple soaps, and is widely used in many coating and poHsh appHcations. 

Discussion. For oils and fats, which are esters of long-chain fatty acids, the saponification value (or number) is defined as the number of milligrams of potassium hydroxide which will neutralise the free fatty acids obtained from the hydrolysis of 1 g of the oil or fat. This means that the saponification number is inversely proportional to the relative molecular masses of the fatty acids obtained from the esters. A typical reaction from the hydrolysis of a glyceride is ... 

A continuous saponification process developed in Leuna is shown in Fig. 9. The saponification reaction... 

Grave wax" is a term for a crumbly, waxy substance called adipocere. Adipocere starts to form on the human body about a month after it is buried. It forms easily on the fatty parts of the body such as the cheeks, abdomen, and buttocks. The waxy adipocere protects the body from further decomposition and has even been found on 10O-year-old exhumed corpses. This buildup occurs when a body is buried in highly basic (alkaline) soil. The waxy substance is produced by a chemical reaction between the basic soil and fats in the body in a process called saponification. Saponification is also the process used in the manufacture of soap. 

Reaction of p-fluorobenzyl chloride with the anion of diethylmethylmalonate ester followed by saponification and decarboxylation leads to acid 9. Polyphosphoric acid cyclization leads to indanone 10. A Reformatsky reaction with zinc amalgam and bromo-acetic ester leads to carbinol 11 which is then... 

Ester saponifaction was a favoured reaction for this type of study, because the hydrophobicity of the acyl moiety could easily be controlled by increasing the length of an n-alkyl group, and saponification of p-nitrophenyl n-alkanoates could be followed with very dilute substrate. Substrate concentration is an important factor, because provided that it is kept low it is reasonable to assume that the micelle structure is relatively unperturbed. 

This saponification reaction can be followed by withdrawing samples from a BR at various times, adding excess standard add to quench the reaction by neutralizing the unreacted hydroxide, and titrating the excess acid with base. In a particular experiment at 16°C, samples of 100 cm3 were withdrawn at various times the concentration of acid used (HC1) was 0.0416 mol L-1. The following results were obtained (V, is the volume of acid solution required to neutralize umeacted NaOH at time /) (Glasstone, 1946, p. 1058). 

PVA Formation Reaction. Poly(vinyl alcohol) is itself a modified polymer being made by the alcoholysis of poly(vinyl acetate) under acid or base catalysis as shown in Equation 1 (6.7). This polymer cannot be made by a direct polymerization because the vinyl alcohol monomer only exists in the tautomeric form of acetaldehyde. This saponification reaction can also be run on vinyl acetate copolymers and this affords a means of making vinyl alcohol copolymers. The homopolymer is water soluble and softens with decomposition at about 200°C while the properties of the copolymers would vary widely. Poly(vinyl alcohol) has been widely utilized in polymer modification because ... 

Write a word equation for the saponification reaction in this lab. 

Chloro, 3-bromo, 3-iodo, and 3-nitro derivatives of 5,7-dimethyl-pyrazolo[l,5-a]pyrimidine derivatives were prepared by chlorination, bromination, iodination, and nitration of 3-unsubstituted 5,7-dimethyl-pyrazolo[l,5-a]pyrimidines. Reaction with bromine and potassium thiocyanate gave a 3-thiocyanato derivative, which was converted into the mercapto derivative upon saponification. Nitrosation gives the 3-nitroso derivative and acylation with trifluoroacetic anhydride affords the trifluoroacetyl derivative (74JMC645 77JMC386). 

A concise preparation of retinoids via new enaminodiesters synthons was described by Valla et al. [41]. For example, all -retinoic acid was synthesized within one day by a one-pot process. The enaminodiester synthon was prepared from methyl isopropylidenemalonate and dimethylformamide dimethylacetal (DMF-DMA) and then condensed with the lithium enolate of (3-ionone. A Grignard reaction with the obtained ketodiester led to the retro carbomethoxyretinoate. Saponification and concomitant decarboxylation, provided mainly all E retinoic acid (all E/ 3Z 90/10, 72% from P-ionone), Fig. (17). 

White et al. developed a stereospecific synthesis of Z-olefins, including isotretinoin [84]. Thus, isotretinoin was obtained by a Reformatsky reaction of p-cyclocitral with the C5 bromoester, followed by DIBAL-H lactone reduction, lactol ring opening, selective olefin bond formation with ethyl 4-diethoxyphosphoryl-3-methyl-2-butenoate and further saponification, Fig. (46). 

This arises, because water accelerates the direct saponification reaction between the EVA and the alkali catalyst. Moreover, water also accelerates the reaction between an acetic acid ester formed as a byproduct in the transesterification and the alkali catalyst. 

Figure 9.1-2. Reactions of organic compounds in high temperature H2O (a), saponification of esters [28] (b), selective reduction of nitro-aromatics [29] (c), the synthesis of quinolones [30].

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