Organic Chemistry – Halogen Derivatives, Alcohols, Carbonyls & Amines

A comprehensive set of vocabulary flashcards covering key terms, reactions, definitions, and concepts from the lecture on halogen derivatives, alcohols, phenols, ethers, aldehydes, ketones, carboxylic acids, and amines.

Halogen Derivative

An organic compound in which one or more hydrogen atoms of a hydrocarbon are replaced by halogen(s).

Haloalkane (Alkyl Halide)

A compound in which a halogen atom is bonded to an sp³-hybridised carbon of an alkyl group (R–X).

Haloalkene

Alkene containing at least one halogen atom bonded to the carbon chain (general example: CH₂=CH–Cl).

Haloalkyne

Alkyne in which a halogen is attached to an sp-hybridised carbon of the –C≡C– group.

Haloarene (Aryl Halide)

Compound where a halogen atom is directly bonded to an sp² carbon of an aromatic ring.

Allylic Halide

Halogen attached to an sp³ carbon next to a C=C double bond (π-allyl position).

Benzylic Halide

Halogen attached to an sp³ carbon directly bonded to an aromatic ring.

Vinylic Halide

Halogen attached directly to an sp² carbon of an alkene.

Markovnikov Rule

In addition of HX to an unsymmetrical alkene, X⁻ attaches to the more substituted carbon (one with fewer H atoms).

Anti-Markovnikov Addition (Peroxide Effect)

In presence of peroxides, HBr adds to alkenes so that Br attaches to the less substituted carbon.

Finkelstein Reaction

Halogen exchange converting R–Cl or R–Br to R–I using NaI in acetone.

Swarts Reaction

Replacement of Cl/Br by F using metallic fluorides like AgF to form alkyl fluorides.

Sandmeyer Reaction

Conversion of aryl diazonium salts to aryl halides (Cl, Br) or cyanides using Cu(I) halides.

Chiral Carbon

A carbon atom bonded to four different atoms/groups, giving optical activity.

Optical Activity

Ability of a substance to rotate the plane of plane-polarised light.

Dextrorotatory (+)

Compound that rotates plane-polarised light to the right (clockwise).

Laevorotatory (–)

Compound rotating plane-polarised light to the left (anticlockwise).

Enantiomers

Non-superimposable mirror-image optical isomers of one another.

Racemic Mixture

Equimolar mixture of two enantiomers showing no net optical rotation.

SN1 Mechanism

Unimolecular nucleophilic substitution proceeding via carbocation intermediate; rate ∝ [substrate].

SN2 Mechanism

Bimolecular nucleophilic substitution via single transition state; rate ∝ [substrate][nucleophile] with inversion of configuration.

Lucas Test

HCl/ZnCl₂ distinguishes alcohol classes: tertiary > secondary > primary by turbidity formation speed.

Hydrogen Bonding

Intermolecular attraction between H attached to electronegative atom (O, N, F) and lone pair on another electronegative atom.

Alcohol (R–OH)

Organic compound with –OH attached to saturated (sp³) carbon.

Phenol (Ar–OH)

Compound with –OH group directly bonded to aromatic ring carbon.

Ether

Compound with an oxygen atom connected to two alkyl/aryl groups (R–O–R).

Monohydric Alcohol

Alcohol containing one hydroxyl group.

Dihydric Alcohol (Glycol)

Alcohol containing two hydroxyl groups (e.g., ethane-1,2-diol).

Trihydric Alcohol

Alcohol containing three hydroxyl groups (e.g., glycerol).

Primary (1º) Alcohol

–OH bearing carbon attached to one other carbon atom.

Secondary (2º) Alcohol

–OH bearing carbon attached to two other carbons.

Tertiary (3º) Alcohol

–OH bearing carbon attached to three other carbons.

Allylic Alcohol

–OH on an sp³ carbon adjacent to a C=C bond.

Benzylic Alcohol

–OH on an sp³ carbon attached to an aromatic ring.

Vinylic Alcohol

–OH directly attached to an sp² carbon of C=C (usually unstable).

Symmetrical (Simple) Ether

Both groups attached to O are the same (e.g., CH₃–O–CH₃).

Williamson Synthesis

Preparation of ethers by reacting alkoxide ion with primary alkyl halide.

Dow Process

Industrial synthesis of phenol from chlorobenzene via NaOH at 623 K/150 atm yielding sodium phenoxide then acidification.

Cumene Process

Production of phenol and acetone via oxidation of cumene to cumene hydroperoxide followed by acid cleavage.

Reimer–Tiemann Reaction

Ortho-formylation of phenols using CHCl₃ and NaOH to yield salicylaldehyde.

Kolbe Reaction

Conversion of sodium phenoxide and CO₂ under pressure to salicylic acid.

Lucas Reagent

Conc. HCl with anhydrous ZnCl₂ used to test alcohol reactivity.

PCC (Pyridinium Chlorochromate)

Anhydrous oxidising agent converting 1º alcohols to aldehydes and 2º alcohols to ketones without over-oxidation.

Clemmensen Reduction

Reduction of carbonyl compounds to hydrocarbons using Zn-Hg amalgam and conc. HCl.

Wolff–Kishner Reduction

Reduction of carbonyl group to CH₂ via hydrazone formation and heating with strong base (KOH) in glycol.

Tollens’ Test

Silver mirror test: aldehydes reduce [Ag(NH₃)₂]⁺ to metallic silver.

Fehling’s Test

Aldehydes reduce Cu²⁺ (complex) to red Cu₂O precipitate.

Schiff Test

Aldehydes restore pink colour to decolourised fuchsine dye.

Haloform Reaction

Methyl ketones react with halogen/alkali to form haloform (e.g., iodoform CHI₃) and carboxylate.

Aldol Condensation

Base-catalysed self-condensation of aldehydes/ketones with α-H to give β-hydroxy carbonyl compounds.

Cannizzaro Reaction

Base-induced disproportionation of aldehydes lacking α-hydrogen into alcohol and carboxylate.

Rosenmund Reduction

Conversion of acyl chloride to aldehyde using H₂ over Pd-BaSO₄ (poisoned catalyst).

Stephen Reaction

Hydrogenation of nitrile with SnCl₂/HCl followed by hydrolysis to yield an aldehyde.

Etard Reaction

Oxidation of methyl group on aromatic ring to aldehyde using CrO₂Cl₂.

Gattermann–Koch Formylation

Formation of benzaldehyde by treating benzene with CO/HCl in presence of AlCl₃ & CuCl.

Acyl Chloride

Derivatives of carboxylic acids where –OH replaced by Cl (R–COCl).

Acid Anhydride

Compound formed by removal of water from two carboxylic acid molecules (R–CO–O–CO–R).

Carboxylic Acid

Compound containing the –COOH functional group.

Decarboxylation

Loss of CO₂ from carboxylate salts with NaOH/CaO giving hydrocarbons.

Grignard Reagent

Organomagnesium halide (RMgX) used to form alcohols, acids etc.

Gabriel Phthalimide Synthesis

Preparation of primary amines via alkylation of potassium phthalimide followed by hydrolysis.

Hofmann Degradation of Amide

Conversion of amide to amine with one fewer carbon using Br₂ & strong base.

Mendius Reduction

Reduction of nitriles to primary amines using LiAlH₄ or Na/ethanol.

Primary (1º) Amine

Amines with formula R–NH₂; one alkyl/aryl group on nitrogen.

Secondary (2º) Amine

Amines with formula R₂NH; two carbon groups on nitrogen.

Tertiary (3º) Amine

Amines with formula R₃N; three carbon groups on nitrogen.

Hinsberg Test

Differentiation of 1º, 2º, 3º amines using benzenesulphonyl chloride and alkali.

Carbylamine Reaction

Primary amines react with CHCl₃/KOH to yield foul-smelling isocyanides (test for 1º amine).

Diazotisation

Conversion of aromatic 1º amines to diazonium salts using NaNO₂/HCl at 273 K.

Sandmeyer (for Amines)

Replacement of diazonium group by Cl, Br, or CN using corresponding Cu(I) salts.

Gattermann Reaction (Diazonium)

Similar to Sandmeyer but using Cu powder + HX to form aryl halide.

Balz–Schiemann Reaction

Conversion of diazonium tetrafluoroborate to aryl fluoride on heating.

Azo Coupling

Reaction of diazonium salts with activated aromatic compounds to form azo dyes (–N=N–).

Hofmann Exhaustive Alkylation

Repeated alkylation of amine → quaternary ammonium salt which undergoes elimination to yield alkene (Hofmann elimination).

Hofmann Elimination

β-Elimination from quaternary ammonium hydroxide giving least substituted alkene (anti-Saytzeff).

Acylation of Amines

Reaction of amine with acid chloride/anhydride to form amide (e.g., C₂H₅NH₂ + CH₃COCl → C₂H₅NHCOCH₃).

Basicity Order (Aliphatic Amines)

2º amine > 1º amine > 3º amine > NH₃ in aqueous phase (due to solvation and inductive effects).

Lucas Reagent Turbidity Order

3º alcohol gives immediate cloudiness; 2º alcohol within minutes; 1º alcohol slow/no reaction at room temp.

Thionyl Chloride Method

Conversion of alcohol to alkyl chloride using SOCl₂ producing SO₂ & HCl gases (clean reaction).

Williamson Ether Limitation

Best with primary halides; secondary/tertiary give elimination.

Oxidation of 1º Alcohol (KMnO₄)

Gives carboxylic acid after passing through aldehyde stage.

Oxidation of 2º Alcohol

Produces ketone; further oxidation difficult without breaking C–C.

Lucas Test Reagent

Conc. HCl + anhydrous ZnCl₂ (Lucas reagent).

FeCl₃ Test for Phenol

Phenols give coloured complexes (violet, blue, green) with FeCl₃ solution.

Esterification (Fischer)

Alcohol/phenol + carboxylic acid in acid medium produce ester and water.

Dehydration of Alcohol

Acid-catalysed elimination of water to give alkene (conditions: conc. H₂SO₄, 413–443 K).

Peroxide Formation in Ethers

Atmospheric O₂ slowly oxidises ethers to explosive peroxides; stored with antioxidants.

Schiff Base (Imine)

Product of aldehyde/ketone with primary amine (R–CH=N–R').

Oxime

Compound formed by reaction of aldehyde/ketone with hydroxylamine (R–CH=N–OH).

Hydrazone

Product of aldehyde/ketone with hydrazine (R–CH=N–NH₂).

2,4-DNPH Test

Aldehydes/ketones form yellow-orange 2,4-dinitrophenylhydrazone precipitates (Brady’s reagent).

Hemiacetal

Intermediate formed when aldehyde adds one molecule of alcohol (–C(OH)(OR)).

Acetal

Product when aldehyde reacts with excess alcohol forming –C(OR)₂ with loss of water (stable in neutral medium).

Ketal

Acetal analogue derived from ketone and diol (cyclic).

Baeyer-Villiger Oxidation (not in notes)

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Zaitsev’s Rule

Noted reverse in Hofmann elimination; major alkene normally most substituted (Zaitsev), but Hofmann gives least substituted.

Freons (CFCs)

Chlorofluorocarbons used as refrigerants/propellants; cause ozone depletion.

DDT

Dichlorodiphenyltrichloroethane; persistent insecticide and pollutant.

Methylene Chloride (CH₂Cl₂)

Volatile solvent; over-exposure causes dizziness and eye damage.

Chloroform (CHCl₃)

Solvent and dichlorocarbene source; CNS depressant, liver toxic.