SUMMARY OF ORGANIC REACTIONS

wSUMMARY OF ORGANIC REACTIONS SECTION 1 - ALIPHATIC Aldehydes and ketones Type of reaction Mechanism 1. oxidation (aldehydes only): aldehyde ( carboxylic acid reagents: potassium dichromate (K2Cr2O7) in sulphuric acid (H2SO4) conditions: warm under reflux equation: R-CHO + [O] ( R-COOH observation: orange to green to distinguish between aldehydes and ketones: either: add Fehling’s solution and heat observation: blue solution to brick red precipitate equation: R-CHO + 4OH- + 2Cu2+ ( R-COOH + Cu2O + 2H2O or: add Tollen’s reagent and heat observation: colourless solution to silver mirror equation: R-CHO + 2[Ag(NH3)2]+ + H2O ( RCOOH + 2Ag + 4NH3 + 2H+ n/a 2. reduction: carbonyl ( alcohol reagents: NaBH4(aq) conditions: room temperature equation: R1-CO-R2 + 2[H] ( R1-CH(OH)-R2 Nucleophilic addition (required) 3. addition of HCN: carbonyl ( hydroxynitrile reagents: NaCN and HCl(aq) conditions: room temperature equation: R1-CO-R2 + HCN ( R1-C(CN)(OH)-R2 Nucleophilic addition (required) Carboxylic acids and their salts Type of reaction Mechanism 1. acid-base a) carboxylic acids with sodium hydroxide reagent: NaOH conditions: room temperature equation: R-COOH(aq) + NaOH(aq) ( R-COO-Na+(aq) + H2O(l) b) carboxylic acids with sodium carbonate reagent: Na2CO3 conditions: room temperature equation: 2R-COOH(aq) + Na2CO3(aq) ( 2R-COO-Na+(aq) + CO2(g) + H2O(l) observations: colourless gas evolved which turns limewater milky c) carboxylate salts with acids reagent: HCl(aq) conditions: room temperature equation: R-COO-(aq) + H+(aq) ( R-COOH(aq) n/a 2. esterification reagents: any alcohol, concentrated sulphuric acid catalyst conditions: heat and reflux equation: R1-COOH + R2OH == R1-COOR2 + H2O Nucleophilic addition/ Elimination (not required) Esters Type of reaction Mechanism hydrolysis a) acid hydrolysis reagent: concentrated H2SO4 conditions: heat under reflux equation: R1-COOR2 + H2O == R1-COOH + R2OH b) alkaline hydrolysis (saponification) reagent: NaOH(aq) conditions: heat under reflux equation: R1-COOR2 + NaOH == R1-COO-Na+ + R2OH n/a Acyl chlorides and acid anhydrides Type of reaction Mechanism 1. acylation using acyl chlorides a) with water (to make carboxylic acids) conditions: room temperature equation: R-COCl + H2O ( R-COOH + HCl observation: white misty fumes b) with ammonia (to make amides) conditions: room temperature equation: R-COCl + NH3 ( R-CONH2 + HCl observation: white misty fumes c) with alcohols (to make esters) conditions: room temperature equation: R1-COCl + R2-OH ( R1-COOR2 + HCl observation: white misty fumes d) with primary amines (to make N-substituted amides) conditions: room temperature equation: R1-COCl + R2-NH2 ( R1-CONHR2 + HCl observation: white misty fumes Nucleophilic addition-elimination (required) 2. acylation using acid anhydrides a) with water (to make carboxylic acids) conditions: room temperature equation: R1-COOCO-R2 + H2O ( R1-COOH + R2-COOH observation: white misty fumes b) with ammonia (to make amides) conditions: room temperature equation: R1-COOCO-R2 + NH3 ( R1-CONH2 + R2-COOH observation: white misty fumes c) with alcohols (to make esters) conditions: room temperature equation: R1-COOCO-R2 + R3-OH ( R1-COO-R3 + R2-COOH observation: white misty fumes d) with primary amines (to make N-substituted amides) conditions: room temperature equation: R1-COOCO-R2 + R3-NH2 ( R1-CONH-R3 + R2-COOH observation: white misty fumes Nucleophilic addition-elimination (not required) Amines Type of reaction Mechanism 1. haloalkane ( primary amine reagents: haloalkane and excess ammonia conditions: heat equation: R-X + 2NH3 ( R-NH2 + NH4X or reagent: haloalkane and ammonia (1:1 ratio) conditions: heat equation: R-X + NH3 ( R-NH2 + HX 2. haloalkane ( secondary amine reagents: haloalkane and ammonia (2:1 ratio) conditions: heat equation: 2R-X + NH3 ( R-NH-R + HX or reagents: haloalkane and primary amine conditions: heat equation: R1-X + R2-NH2 ( R1-NH-R2 + HX 3. haloalkane ( tertiary amine reagents: haloalkane and ammonia (3:1 ratio) conditions: heat equation: 3R-X + NH3 ( R3N + HX or reagents: haloalkane and secondary amine conditions: heat equation: R1-X + R2-NH-R3 ( R1R2R3N + HX 4. haloalkane ( quartenary ammonium salt reagents: haloalkane and ammonia (4:1 ratio) conditions: heat equation: 4R-X + NH3 ( [R4N]+X- or reagents: haloalkane and secondary amine conditions: heat equation: R1-X + R2R3R4N ( [R1R2R3R4N]+X- Nucleophilic substitution (required) 2. reduction: nitrile ( primary amine reagents: LiAlH4 in dry ether conditions: room temperature equation: R-CN + 4[H] ( R-CH2NH2 n/a 3. acid-base: a) amines with acids equations: R1-NH2 + HCl ( R1-NH3Cl R1R2-NH + HCl ( R1R2-NH2Cl R1R2R3-N + HCl ( R1R2R3-NHCl b) alkyl ammonium salts with alkalis equations: R1-NH3Cl + NaOH ( R1-NH2 + NaCl + H2O R1R2-NH2Cl + NaOH ( R1R2-NH + NaCl + H2O R1R2R3-NHCl + NaOH ( R1R2R3-N + NaCl + H2O n/a Amino Acids Type of reaction Mechanism 1. acid-base reactions of amino acids a) with acids reagents: HCl conditions: room temperature equation: R-CH(NH2)-COOH + HCl ( R-CH(NH3+Cl-)-COOH b) with alkalis reagents: NaOH conditions: room temperature equation: R-CH(NH2)-COOH + NaOH (R-CH(NH2)-COO-Na+ + H2O 2. condensation reactions of amino acids conditions: DNA equation: n R-CH(NH2)-COOH ( H-(NHCRHCO)n-OH + (n-1) H2O 3. hydrolysis of proteins reagents: 6 moldm-3 HCl conditions: heat, reflux equation: H-(NHCRHCO)n-OH + (n-1) H2O + n HCl ( n R-CH(NH3+Cl-)-COOH Nucleophilic addition-elimination (not required) Polymers Type of reaction Mechanism 1. Addition polymerisation (alkenes ( polyalkenes) conditions: high temperature, Ziegle-Natte catalyst equation: 2. Condensation polymerisation a) polyesters dicarboxylic acid + diol ( polyester conditions: H2SO4, heat under reflux equation: or diacyl chloride + diol ( polyester conditions: room temperature equation: b) polyamides dicarboxylic acid + diamine ( polyamide conditions: warm, reflux equation: or diacyl chloride + diamine ( polyamide conditions: room temperature equation: Free radical addition (not required) Nucleophilic addition-elimination (not required) 3. Hydrolysis of condensation polymers a) polyesters reagents: NaOH(aq) conditions: heat equation: b) polyamides reagents: HCl(aq) conditions: heat equation: n/a n/a SECTION 2 – AROMATIC Type of reaction Mechanism 1. nitration (benzene ( nitrobenzene) Reagent: conc HNO3 in conc H2SO4 Conditions: 50-55oC under reflux Equation: C6H6 + HNO3 ( C6H5NO2 + H2O Electrophilic substitution (required) 2. alkylation (benzene ( alkylbenzene) Reagent: R-Cl with anyhdrous AlCl3 Conditions: 50oC under reflux Equation: C6H6 + R-Cl ( C6H5-R + HCl OR Reagent: alkene with anhydrous AlCl3 and HCl Equation: C6H6 + R1R2C=CR1R2 ( C6H5CR1R2CR3R4 Electrophilic substitution (required) 3. acylation (benzene ( phenylketone) Reagent: R-COCl with anydrous AlCl3 Conditions: 50oC under reflux Equation: C6H6 + R-COCl ( C6H5COR + HCl Electrophilic substitution (required) 4. reduction (nitrobenzene ( phenylamine) Reagents: Sn in conc HCl Conditions: heat under reflux Equation: C6H5NO2 + 6[H] ( C6H5NH2 + 2H2O n/a