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This page contains tables of azeotrope data for various binary and ternary mixtures of solvents. The data include the composition of a mixture by weight (in binary azeotropes, when only one fraction is given, it is the fraction of the second component), the boiling point (b.p.) of a component, the boiling point of a mixture, and the specific gravity of the mixture.
The classic example of a dehydration reaction is the Fischer esterification, which involves treating a carboxylic acid with an alcohol to give an ester RCO 2 H + R′OH ⇌ RCO 2 R′ + H 2 O. Often such reactions require the presence of a dehydrating agent, i.e. a substance that reacts with water.
Reaction mechanism for the amine formation from a carboxylic acid via Schmidt reaction. In the reaction mechanism for the Schmidt reaction of ketones, the carbonyl group is activated by protonation for nucleophilic addition by the azide, forming azidohydrin 3, which loses water in an elimination reaction to diazoiminium 5.
Alkaline hydrolysis of esters is also known as saponification. A base such as sodium hydroxide is required in stochiometric amounts. Unlike acid-catalyzed ester hydrolysis, it is not an equilibrium reaction and proceeds to completion. Hydroxide ion attacks the carbonyl carbon to give a tetrahedral intermediate, which then expels an alkoxide ion.
A well-known example of a positive azeotrope is an ethanol–water mixture (obtained by fermentation of sugars) consisting of 95.63% ethanol and 4.37% water (by mass), which boils at 78.2 °C. [10] Ethanol boils at 78.4 °C, water boils at 100 °C, but the azeotrope boils at 78.2 °C, which is lower than either of its constituents. [ 11 ]
This reaction is related to several classic named reactions: The acylated reaction product can be converted into the alkylated product via a Clemmensen or a Wolff-Kishner reduction. [17] The Gattermann–Koch reaction can be used to synthesize benzaldehyde from benzene. [18] The Gatterman reaction describes arene reactions with hydrocyanic acid ...
Scheme 2. Hydrolysis of benzoic acid esters. Reaction constants are known for many other reactions and equilibria. Here is a selection of those provided by Hammett himself (with their values in parentheses): the hydrolysis of substituted cinnamic acid ester in ethanol/water (+1.267) the ionization of substituted phenols in water (+2.008)
The Piria reaction. In the Tyrer sulfonation process (1917), [7] at some time of technological importance, benzene vapor is led through a vessel containing 90% sulfuric acid the temperature of which is increased from 100 to 180°C. Water and benzene are continuously removed and the benzene fed back to the vessel. In this way an 80% yield is ...