Organic Name Reactions

Bakelite Formaldehyde condenses with phenol to give a synthetic plastic Bakelite

Phenol is refluxed with formalin and ammonia (catalyst) when an oil separates. The oily liquid is transferred to an open vessel and heated until a test sample, on cooling in water, is found to be hard & brittle. It is then left to cool to give bakelite.

Diels alder reaction This involves the treatment of 1,3-butadiene (or any other conjugated diene) with an alkene or an alkyne. No catalyst is required The alkene or alkyne used in diels-alder reaction is referred to as Dienophile (diene lover) The product of diels-alder reaction is called the adduct. The net result is the formation of two new σ bonds and one new π bond at the expense of three original π bonds.

Dienophile Adduct Diene

Friedel-Craft Reaction Friedel craft alkylation: Benzene reacts with alkyl halides in the presence of aluminum chloride to form alkyl benzene. Mechanism

Friedel-Craft Acylation: Benzene reacts with acid chlorides (or anhydrides) in the presence of aluminium chloride to give aromatic ketones. Mechanism

Gabriel Phthalimide Synthesis This involve the treatment of phthalimide with potassium hydroxide to form the potassium salt. The salt is then heated with an alkyl halide to give N-alkyl phthalimide, which in turn reacts with potassium hydroxide to form potassium phthalate salt and a pure primary amine.

Phthalimide Potassium phthalimide N-Alkylphthalimide Potassium phthalate

Clemmensen Reduction This involves the use of zinc-mercury amalgam in hydrochloric acid as a reducing agent Aldehydes & Ketones can be reduced to alkanes by this method

Wolf-Kishner Reduction This involves the use of a basic solution of hydrazine as the reducing agent Aldehydes & Ketones can be reduced to alkanes by this method

Reimer-Tiemann Reaction This involves the treatment of phenol with chloroform in the aqueous sodium hydroxide solution followed by acid hydrolysis, salicylaldehyde is formed. If carbon tetrachloride is used in place of chloroform, salicylic acid is formed

Cannizzaro Reaction Aldehydes which lack an α-H, when heated with concentrated NaOH, undergo a disproportionation reaction One half of the aldehyde molecules are oxidized to a carboxylic acid and one half are reduced to an alcohol. This reaction is known as Cannizzaro Reaction

Gattermann-Koch Synthesis This involves the treatment of benzene with corbon monoxide and hydrogen chloride in presence of AlCl3 catalyst.

Mechanism Step 1: Carbon mono oxide and HCl react to form unstable formyl chloride. Step 2: Formation of the electrophile

Step 3: The electrophile attacks the benzene ring to give a carbonium ion. Step 4: Removal of proton gives benzaldehyde.

Rosenmund Reduction This involves the treatment of benzoyl chloride with hydrogen in the presence of palladium catalyst “Poisoned” with barium sulphate.

Sandmeyer Reaction When a cold diazonium salt solution is treated with cuprous chloride, cuprous bromide or cuprous cyanide, the product is aryl chloride, aryl bromide or aryl nitrile. These reactions are known as Sandmeyer reactions.

Wacker Process Both aldehyde and ketones can be prepared by this method. This process involves the treatment of an alkene with and acidified aqueous solution of palladium chloride and cupric chloride. For example,

Wurtz Synthesis Higher alkanes are produces by heating an alkyl halide (RX) with sodium methal in dry ether solution. Two molecules of the alkyl halide lose their halogen atoms as NaX. The net result is the joining of two alkyl groups to yield a symmetrical alkane (R-R) having an even number of carbon atoms.

Wurtz-fittig Reaction Aryl halides couple with alkyl halides when heated with sodium in ether solution, to form alkyl benzenes.

Ullmann Reaction Aryl iodides and bromides when heated with copper form biaryl compounds in which two benzenes rings are bonded together.

Baeyer–Villiger oxidation The Baeyer-Villiger oxidation (also called Baeyer-Villiger rearrangement) is an organic reaction that forms an ester (ROR) from a ketone or a lactone from a cyclic ketone. Peroxy acids or peroxides are used as the oxidant. The reaction is named after Adolf Baeyer and Victor Villiger who first reported the reaction in 1899.

Reaction mechanism In the first step of the reaction mechanism, the peroxyacid protonates the oxygen of the carbonyl group. This makes the carbonyl group more susceptible to attack by the peroxyacid. In the next step of the reaction mechanism, the peroxyacid attacks the carbon of the carbonyl group forming what is known as the Criegee intermediate. (Read: Criegee rearrangement)

Through a concerted mechanism, one of the substituents on the ketone migrates to the oxygen of the peroxide group while a carboxylic acid leaves. This migration step is thought to be the rate determining step. Finally, deprotonation of the oxygen of the carbonyl group produces the ester.

Step:1

Step:2

Step:3

Step:4

Steroids are an important class of molecules for use in therapeutics. For instance, testololactone has been identified as an anticancer agent. In 2013, Alina Świzdor reported the transformation of dehydroepiandrosterone to testololactone by use of a fungus that produces Baeyer-Villiger monooxygenases. The fungus formed testololactone from dehydroepiandrosterone via a Baeyer-Villiger oxidation

Birch reduction The reaction was reported in 1944 by the Australian chemist Arthur Birch It converts aromatic compounds having a benzenoid ring into a product, 1,4-cyclohexadienes, in which two hydrogen atoms have been attached on opposite ends of the molecule. It is the organic reduction of aromatic rings in liquid ammonia with sodium, lithium or potassium and an alcohol, such as ethanol and tert-butanol. This reaction is quite unlike catalytic hydrogenation, which usually reduces the aromatic ring all the way to a cyclohexane.

An example is the reduction of naphthalene

Basic reaction mechanism A solution of sodium in liquid ammonia consists of the electride salt [Na(NH3)x]+ e−, associated with the intense blue color of these solutions. The solvated electrons add to the aromatic ring to give a radical anion (the arrows depicting the movement of the single electrons should be 'fish-hook' arrows). The added alcohol supplies a proton to the radical anion and also to the penultimate carbanion; for most substrates ammonia is not acidic enough.

Eschweiler–Clarke reaction The Eschweiler–Clarke reaction (also called the Eschweiler–Clarke methylation) is a chemical reaction whereby a primary (or secondary) amine is methylated using excess formic acid and formaldehyde. Reductive amination reactions such as this one will not produce quaternary ammonium salts, but instead will stop at the tertiary amine stage. It is named for the German chemist Wilhelm Eschweiler and the British chemist Hans Thacher Clarke

Mechanism The first methylation of the amine begins with imine formation with formaldehyde. The formic acid acts as a source of hydride and reduces the imine to a secondary amine. The driving force is the formation of the gas carbon dioxide. Formation of the tertiary amine is similar, but slower due to the difficulties in iminium ion formation.

Perkin Reaction The Perkin reaction is an organic reaction developed by William Henry Perkin that is used to make cinnamic acids. It gives an α,β-unsaturated aromatic acid by the aldol condensation of an aromatic aldehyde and an acid anhydride, in the presence of an alkali salt of the acid. The alkali salt acts as a base catalyst, and other bases can be used instead.

Mechanism