Ch 12Organic Compounds Containing Nitrogen — Class 12 Chemistry, concept-first.

Chemistry organizes the compounds of carbon by their functional group -- the atom or group of atoms that gives a molecule its characteristic reactivity -- and nitrogen forms four functionally distinct…

A nitro compound has the general structure , in which the nitrogen atom is bonded directly to a carbon of the organic skeleton and carries a formal positive charge balanced by a delocalised negative c…

General preparation of nitroalkanes. A primary or secondary haloalkane, heated with alcoholic silver nitrite (), undergoes nucleophilic substitution to give predominantly the nitroalkane: The nitrite…

Structure. In every amine, nitrogen retains one lone pair of electrons and forms three bonds -- to hydrogen and/or carbon -- giving it, like ammonia, a pyramidal () shape with the lone pair occupying…

Four distinct synthetic methods are used to build up an amine, most often a primary amine, and each has its own scope and limitation -- so choosing the RIGHT method for a given target amine is as impo…

Three independent starting materials all converge on a primary amine by simple reduction:

Heating a haloalkane with an excess of ethanolic ammonia in a sealed tube at elevated temperature and pressure (ammonolysis) substitutes the halogen by an amino group: On paper this looks like a clean…

The Gabriel phthalimide synthesis solves ammonolysis's over-alkylation problem by protecting the nitrogen inside a ring until the very last step, so it can never react more than once:

The Hoffmann bromamide degradation reaction converts an amide directly into a primary amine that has ONE FEWER carbon than the starting amide -- the only method in this chapter that shortens the chain…

Amines show intermediate physical properties, positioned chemically between hydrocarbons (no hydrogen bonding at all) and alcohols (strong hydrogen bonding), because nitrogen is less electronegative t…

An amine is basic because nitrogen's lone pair of electrons is available to accept a proton, forming an alkylammonium (or anilinium) ion.

Alkylation. An amine's nucleophilic nitrogen attacks an alkyl halide in a straightforward substitution, exactly as ammonia does in ammonolysis (Section 25.5.2), and suffers from the identical problem:…

Nitrous acid (), always generated in situ from and a mineral acid ( or ) because it is unstable when isolated, reacts with each class of amine in a chemically distinct way -- making this reaction a po…

The Hinsberg test distinguishes primary, secondary and tertiary amines by exploiting a difference in the ACIDITY of the sulphonamide products formed when each is treated with benzenesulphonyl chloride…

Cyanides (also called nitriles or alkyl cyanides) and isocyanides (also called carbylamines or isonitriles) are built on the same two-atom unit and share the molecular formula , yet they are genuinely…

Both cyanides and isocyanides are made from the identical starting material -- a haloalkane -- and the identical pseudohalide ion, ; the ONLY variable that decides which isomer forms is which METAL SA…

Although cyanides and isocyanides are constitutional isomers of each other, their hydrolysis and reduction chemistry diverges sharply, precisely because the identity of the atom bonded to (carbon in o…

Diazotization is the reaction by which an AROMATIC primary amine is converted into an arenediazonium salt, using sodium nitrite and a mineral acid (usually ) generated as nitrous acid in situ, held at…

The diazonium group, , is an outstanding leaving group -- nitrogen gas is an exceptionally stable, low-energy molecule to depart as -- so a very wide range of nucleophiles and metal catalysts can disp…

Instead of losing nitrogen, a diazonium salt can instead RETAIN it, if it reacts with a sufficiently electron-rich aromatic partner -- a phenol or an aromatic amine -- under mild, typically alkaline (…

Diazonium salts occupy a uniquely important place in synthetic organic chemistry because they let a chemist install, at a chosen position on a benzene ring, a substituent that DIRECT electrophilic aro…

This chapter followed four nitrogen-containing organic families in the order set by WBCHSE's own Unit 6 syllabus.

Sample papers and previous-year board questions for this subject.