CH3<\/sub>COOCH2<\/sub>CH3<\/sub>\n+ H2<\/sub>O \u21cb CH3<\/sub>COOH + CH3<\/sub>CH2<\/sub>OH<\/p>\n\n\n\n Ethyl ethanote ethanoic acid ethanol<\/p>\n\n\n\n Another example hydrolyzing methyl\nproponate<\/p>\n\n\n\n \nH+<\/sup>(aq)<\/sub><\/p>\n\n\n\n \nCH3<\/sub>CH2<\/sub>COOCH3<\/sub> + H2<\/sub>O \u21cb \nCH3<\/sub>CH2<\/sub>COOH + CH3<\/sub>OH<\/p>\n\n\n\n \nMethyl propanoate \npropanoic acid methanol<\/p>\n\n\n\n The reactions are reversible, use excess\namount of water to make the hydrolysis as complete as possible, the water comes\nfrom dilute acid so ester mix with excess of dilute acid.<\/p>\n\n\n\n Sodium hydroxide is used to hydrolyzing\nester, ester are heated with dilute alkali like sodium hydroxide. The reaction\nis one way and the products are easily separated.<\/p>\n\n\n\n \nCH3<\/sub>COOCH2<\/sub>CH3<\/sub> + NaOH \u2192 CH3<\/sub>COONa + CH3<\/sub>CH2<\/sub>OH<\/p>\n\n\n\n \nEthyl ethanoate \nsodium ethanoate ethanol<\/p>\n\n\n\n Hydrolyzing methyl propanote in the same\nway<\/p>\n\n\n\n \nCH3<\/sub>CH2<\/sub>COOCH3<\/sub> + NaOH \u2192 CH3<\/sub>CH2<\/sub>COONa + CH3<\/sub>OH<\/p>\n\n\n\n Methyl propanote sodium propanote methanol<\/p>\n\n\n\n Ester was first reported by German chemist Leopold Gmelin in first half of 19th<\/sup> century, class of organic compound, structurally an alkoxy (OR) group is attached to the carbonyl group. They react with water and produced alcohols and organic or inorganic acids. In reactions alkoxy group is replaced by another group like hydrolysis which means splitting with water. It is catalyzed by either through base or an acid like hydrochloric acid or sulfuric acid. It is the reverse process of esterification (preparation of an ester). R may be alkyl, aryl or may be H [2]. It can be prepared through reactions of acid anhydride with alcohol and reaction of carboxylic acid salts with alkyl halides. Esters can be converted into another type of ester through transesterified process, in which through reaction with an alcohol, a carboxylic acid or third ester in the presence of catalyst. Saponification is the process in which ester hydrolysis is carried out in the presence of alkalies, it is used in the preparation of soaps from fat or oils, also helpful for quantitative estimation of ester.<\/p>\n\n\n\n Ester<\/p>\n\n\n\n The\nester first word is derived from alkyl group and second word is from\ncarboxylate group of the carboxylic acid.<\/p>\n\n\n\n Ester are most commonly prepared through the reactions of carboxylic acid, acid chlorides and acid anhydrides with alcohol [3].<\/p>\n\n\n\n Acid \u2013 Catalyzed Esterification<\/strong><\/p>\n\n\n\n The\nreaction of carboxylic acid and alcohol forms ester. The catalytic amount of a\nstrong inorganic acid like sulfuric acid (H2<\/sub>SO4<\/sub>),\nHydrochloric acid (HCl) and H3<\/sub>PO4<\/sub> while organic acid include benzenesulpohonic\nor \u03c1- toluenesulphonic acid are used because they are soluble in organic\nsolvent and they are also used as catalyst without adding additional amount of\nwater<\/p>\n\n\n\n In\nthe process of acid hydrolysis ester is heated with large amount of water which\ncontain a strong acid catalyst. This reaction is reversible and does not go for\ncompletion like esterification.<\/p>\n\n\n\n For\nexample: butyl acetate reacts with water to produce acetic acid and 1- butanol.<\/p>\n\n\n\n CH3<\/sub>COOCH2<\/sub>CH3<\/sub>CH3<\/sub>\n+ H2<\/sub>O \u21cb CH3<\/sub>COOH + CH3<\/sub>CH2<\/sub>CH2<\/sub>CH2<\/sub>OH<\/p>\n\n\n\n Butyl acetate water \n Acetic acid 1- Butanol (butyl alcohol)<\/p>\n\n\n\n Esters derived from an Acid chloride\nand an Alcohol<\/strong><\/p>\n\n\n\n Acid\nchloride and alcohol reacts with each other in the presence of a base like pyridine\nor Na2<\/sub>CO3<\/sub> to make esters, the weak base is neutralize the\nliberated HCl.<\/p>\n\n\n\n \nPyridine<\/p>\n\n\n\n Butanoyl chloride\n+ Ethanol \u2192 Ethyl butanoate + hydrochloric acid<\/p>\n\n\n\n Ester derived from an Acid Anhydride\nand an Alcohol or a Phenol<\/strong><\/p>\n\n\n\n Acid anhydride react with phenol or alcohol via nucleophilic acyl substitution to produce ester in the presence of a catalyst like strong acid (H2<\/sub>SO4<\/sub>) or a weak base (pyridine) or through heating.<\/p>\n\n\n\n Hydrolyzing complicated esters for\nsoap making<\/strong><\/p>\n\n\n\n Hydrolyzing big ester are commonly found in animals and vegetables fats or oils. Large esters are heated with concentrated sodium hydroxide produce a salt of carboxylic acid and octadecanoic acid (stearic acid). The salt is very important by-product which is helpful in cleaning. An alcohol is also produced called as propane-1,2,3-triol (glycerol).<\/p>\n\n\n\n The\nalkaline hydrolysis of an ester called as saponification.<\/p>\n\n\n\n First step<\/strong><\/p>\n\n\n\n Activate\nthe ester because an acid\/base reaction, weak nucleophile and a poor\nelectrophile is present. So the protonation of the ester carbonyl make it more\nelectrophilic [4].<\/p>\n\n\n\n Second step<\/strong><\/p>\n\n\n\n The\noxygen (O) of water function as nucleophile attack on the electrophilic C in\nthe C=O and electron moving towards oxonium ion, making tetrahedral\nintermediate.<\/p>\n\n\n\n Third step<\/strong><\/p>\n\n\n\n Deprotonate\nthe oxygen which is came from the water molecules and neutralize the charge.<\/p>\n\n\n\n Fourth step<\/strong><\/p>\n\n\n\n There\nis a need to make the \u2013OCH3<\/sub> leave, but first protonation and then\nconvert it into good leaving group.<\/p>\n\n\n\n Fifth step<\/strong><\/p>\n\n\n\n With\nthe help of electron of adjacent oxygen \u201cpush out\u201d the leaving group called\nneutral methanol molecule.<\/p>\n\n\n\n Sixth step<\/strong><\/p>\n\n\n\n Now deprotonation of the oxonium ion make carbonyl C=O in the carboxylic acid product and reproduce the acid catalyst.<\/p>\n\n\n\n First step<\/strong><\/p>\n\n\n\n The\nhydroxide nucleophiles attack on the electrophilic C of the ester compound C=O,\nthey break the double bond and make the tetrahedral intermediate.<\/p>\n\n\n\n Second step<\/strong><\/p>\n\n\n\n The\nintermediate collapses and again form the C=O results in the loss of alkoxide\nleaving group, leading to the carboxylic acid.<\/p>\n\n\n\n Third step<\/strong><\/p>\n\n\n\n Equilibrium is formed where alkoxide, RO–<\/sup> behave as a base deprotonating the carboxylic acid, RCO2<\/sub>H.<\/p>\n\n\n\n Hydrolysis It means cleavage of chemical bonds of compound through the addition of water. During hydrolysis reaction with pure water is slow and usually not used, but ester is catalyzed by dilute acid like dilute hydrochloric acid and dilute sulphuric acid [1]. For example: H+ (aq) CH3COOCH2CH3 + H2O \u21cb CH3COOH + CH3CH2OH … Read more<\/a><\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"rating_form_position":"","rating_results_position":"","mr_structured_data_type":""},"categories":[7],"tags":[],"multi-rating":{"mr_rating_results":[{"adjusted_star_result":5,"star_result":5,"total_max_option_value":5,"adjusted_score_result":5,"score_result":5,"percentage_result":100,"adjusted_percentage_result":100,"count":1,"post_id":1163}]},"_links":{"self":[{"href":"https:\/\/chemdictionary.org\/wp-json\/wp\/v2\/posts\/1163"}],"collection":[{"href":"https:\/\/chemdictionary.org\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/chemdictionary.org\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/chemdictionary.org\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/chemdictionary.org\/wp-json\/wp\/v2\/comments?post=1163"}],"version-history":[{"count":5,"href":"https:\/\/chemdictionary.org\/wp-json\/wp\/v2\/posts\/1163\/revisions"}],"predecessor-version":[{"id":1310,"href":"https:\/\/chemdictionary.org\/wp-json\/wp\/v2\/posts\/1163\/revisions\/1310"}],"wp:attachment":[{"href":"https:\/\/chemdictionary.org\/wp-json\/wp\/v2\/media?parent=1163"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/chemdictionary.org\/wp-json\/wp\/v2\/categories?post=1163"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/chemdictionary.org\/wp-json\/wp\/v2\/tags?post=1163"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Hydrolysis through dilute alkali<\/h2>\n\n\n\n
Ester<\/h2>\n\n\n\n
![\"\"](\"https:\/\/chemdictionary.org\/wp-content\/uploads\/2019\/11\/image-31.png\")
<\/figure><\/div>\n\n\n\nNomenclature of Ester<\/h2>\n\n\n\n
Preparation of Ester<\/h2>\n\n\n\n
![\"\"](\"https:\/\/chemdictionary.org\/wp-content\/uploads\/2019\/11\/image-51.png\")
<\/figure>\n\n\n\nSynthesis of Ester<\/h2>\n\n\n\n
![\"\"](\"https:\/\/chemdictionary.org\/wp-content\/uploads\/2019\/11\/image-52.png\")
<\/figure>\n\n\n\n![\"\"](\"https:\/\/chemdictionary.org\/wp-content\/uploads\/2019\/11\/image-53.png\")
<\/figure>\n\n\n\nUses and Application<\/h2>\n\n\n\n
Mechanism of the acid catalyzed hydrolysis of esters<\/h2>\n\n\n\n
![\"\"](\"https:\/\/chemdictionary.org\/wp-content\/uploads\/2019\/11\/image-54.png\")
<\/figure>\n\n\n\nMechanism of base hydrolysis of Esters<\/h2>\n\n\n\n
![\"\"](\"https:\/\/chemdictionary.org\/wp-content\/uploads\/2019\/11\/image-55.png\")
<\/figure>\n\n\n\nApplications of Ester Hydrolysis<\/h2>\n\n\n\n
References <\/h4>\n\n\n\n