Organic Chemistry Reactions for H2 Chemistry, A-Levels

Compound Alkene (C=C)

Alkane Halogenoalkane (R-X)

Reactions undergone Nucleophilic addition

With what compound? H2, (Ni catalyst, 150°C or Pt catalyst) Catalytic hydrogenation HX (RT), X is halogen Electrophilic addition Concentrated H2SO4, water

What is formed Alkane

Oxidation with KMnO4

CHR end of alkene CR’R end of alkene CH2 end of terminal alkene X2, X is halogen

Aldehyde Ketone CO2, H2O Halogenoalkane

NaOH, Reflux NaCN, ethanolic, heat

Alcohol Nitrile

Excess ammonia Concentrated NaOH in ethanol, reflux Cr2O72- or KMnO4, acidified

Amine Alkene

Free radical substitution Nucleophilic substitution

Elimination Alcohol (–OH)

Oxidation

Nucleophilic substitution Dehydration Iodoform test

PBr3, concentrated H2SO4, refluxed H2SO4, heat Iodine and sodium hydroxide

Halogenoalkane Alcohol

Aldehyde

Ketone Halogenoalkane Alkene Carboxylate ion

Remarks

Position depends on stability and where the C=C double bond was (Markovnikov’s rule)

Effervescence observed in QA Markovnikov’s rule applies (stability and position) OH group replaces halogen CN group replaces halogen. One extra Carbon.

Primary alcohol becomes this *To get an aldehyde, use K2Cr2O7 acidified, heat w/ immediate distillation Secondary alcohol becomes this

2 products, look at –OH group Pale yellow precipitate of CHI3 formed.

Aldehyde

Ketone

Oxidation

Tollens’ Reagent, warm Fehling’s Solution, warm I2 (aq), NaOH, warm K2Cr2O7 or KMnO4 oxidized

Carboxylate ion Carboxylate ion Carboxylate ion Carboxylic acid

Nucleophilic addition

Condensation

HCN, KOH HCN, KCN KCN, H2SO4 2, 4-DNPH

Reduction Oxidation

LiAlH4, dry ether I2 (aq), NaOH, warm

Nitrile with alcohol group *Cyanohydrin Orange precipitate Primary alcohol Carboxylate ion

Nucleophilic addition

HCN, KOH HCN, KCN KCN, H2SO4 2, 4-DNPH

Condensation Carboxylic acid

Fission of C-O bond

Nitrile

Reduction Acidic hydrolysis

Alcohol, R-OH, with concentrated H2SO4, heat PCl5 or SOCl2 LiAlH4, dry ether Dilute HCl

Reduction Hydrolysis Nucleophilic

LiAlH4, dry ether Water Alcohol

Acyl chloride

Nitrile with alcohol group *Cyanohydrin Orange precipitate Ester Acyl chloride Alcohol Carboxylic acid Amine Carboxylic acid Ester

Silver mirror formed Red PPT of Cu2O formed Yellow PPT of CHI3 formed From primary alcohol, can go straight to this One extra carbon than before

C=O bond cutaway

Yellow PPT of CHI3 formed. This only happens with methyl ketones One extra carbon than before (step up reaction) C=O bond cutaway H2SO4 acts as a catalyst White fumes observed as well Ammonium chloride produced as a side product HCl byproduct

substitution Benzene *remark: ALL benzene reactions apply for methylbenzene as well. *remark: the CH3 on methylbenzene behaves like a typical alkane.

Methylbenzene Specific Phenol

Electrophilic substitution

Addition Oxidation

Acylation Electrophilic substitution

Phenol Amine, ammonia Concentrated HNO3 Concentrated H2SO4 30°C Cl2, AlCl3

Ester Amide

Alkaline medium PREFERRED 2,4 directing for methylbenzene

2,4 directing for methylbenzene

Br2, FeBr3

2,4 directing for methylbenzene

RCl, AlCl3 (Friedel-Crafts Alkylation)

2,4 directing for methylbenzene Diagram is inaccurate

Acyl chloride, AlCl3 H2, Ni Cr2O72- or KMnO4, acidified

Ester Cyclohexane Benzoic acid

Acyl chloride Br2 in CCl4, room temperature Br2 (aq) Dilute HNO3, room temperature Concentrated HNO3, room temperature

Ester Phenol with 1 Br Phenol with 3 Br Phenol with 1 NO2 Phenol with 3 NO2

2,4 directing for methylbenzene EVERY SINGLE BENZENE RING WITH ANY ALKYL GROUP ATTACHED DOES THIS. White fumes of HCl evolved 2,4 directing, applies to Cl2 as well 2 next to, 1 opposite 2,4 directing 2 next to, 1 opposite

Distinguishing tests to confirm what’s what - 2,4 DNPH: Used to confirm presence of aldehydes or ketones - Sodium Carbonate: Only carboxylic acids react with it - Iodoform test: Used to confirm presence of CH3CO group, as with a methyl-aldehyde, methyl ketone or methyl alcohol. - Aqueous Bromine: Decolorizes when alkenes and phenols are present - Bromine in CCl4: Decolorizes N-phenyl-ethanamides, (phenylamines,) phenols and alkenes. - Tollens’ Reagent: Oxidizes aldehydes and benzaldehydes to form a silver mirror (Ag) - Fehling’s Reagent: Oxidizes aldehydes to form a reddish brown precipitate of copper (I) oxide. o Can’t oxidize benzaldehydes because alkaline condition causes benzaldehyde to disproportionate. - Neutral iron (III) chloride: reacts with phenols to form a violet coloration