Class 12 Organic Chemistry Cheat Sheet PDF

# Class 12 Organic Chemistry Cheat Notes ## Name Reactions - **Aldol Condensation:** CH3-C=O + H-CH2CHO → CH3-CH2-CH2CHO H H - **Cross Aldol Condensation:** CH3-CH + H -C-H → HO-CH2-CH-C-H dil. NaOH - **Balz-Schiemann Reaction:** NH2+NaNO2/HBF4 → F + N2+BF3 Fluorobenzene Aniline - **Benzoin Condensation:** O O || || C-H + H-C → C-C || || O O Benzoin - **Cannizzaro Reaction:** 2(H-C-H) + NaOH → CH3OH + H-C-ONa CHO + NaOH → C6H5OH + C6H5COONa Benzyl alcohol Sod. Benzoate - **Carbyl Amine Reaction:** CH3CH2NH2 + CHCl3 + 3KOH → CH3-CH2-N=C + 3KCl + 3H2O - **Clemmensen Reduction:** CH3COCH3 + 4[H] → CH3CH2CH3 + H2O COCH3 + 4[H] → CH2CH3 + H2O - **Decarboxylation Reaction:** COOH + 2NaOH → Na2CO3 + H2O COO H - **Coupling Reaction:** OH OH +N2Cl → O2S-N2OH + HCl p-hydroxy azobenzene N2Cl + NH2 → O2S-NH2 p-Amino azobenzene - **Diazotization Reaction:** NH2 + HONO + HCl → HONO + H2O Nitrous Acid - **Etard Reaction:** CH3 → (H-(O=Cr(OH)Cl2)2 → (H-(O=Cr(OH)Cl2)2 → CHO CCl4 Hydrolysis Benzaldehyde Toluene Brown Complex - **Finkelstein Reaction:** C2H5-Br + NaI → C2H5-I + NaBr Acefone/ - **Fittig Reaction:** Cl + 2Na + Cl → + 2NaCl Dry Ether - **Friedal Craft Reaction:** i) Alkylation: Anhy CH3 +CH3Cl ΑlCl3 + HCl → Toluene ii) Acylation: COCH3 Anhy +CH3COCl AlCl3 + HCl → Acephenone - **Gattermann Reaction:** C/HCl + N2 Cu/HBr +N2 - **Gabriel Phthalimide Synthesis:** CO NH Phthalimide CO + KOH → CO NK + C2H5I → CO NC2H5 + 2H2O → COOK + C2H5-NH2 H+ Pot-Phthalimide N-Ethyl phthalimide Phthalic Acid - **Gattermann Koch Reaction:** CHO +CO + HCl → + HCl Alch+CuCl Benzaldehyde - **H.V.Z Reaction** (Hell Volhard Zelinsky Reaction): CH3COOH + Cl2 → Cl2 C-COOH + Cl2 → Ch2ClCOOH - **Hofmann Ammonolysis:** 1o amine Cl2/Redp 2o amine Cl2/Redp 3o amine H2N + R-X → R-NH2 + R-X → R-NH-R + R-X → R-N-R -HX -HX -HX - **Hofmann Bromamide Degradation:** R-CONH2 + Br2 + 4NaOH → R-NH2 + 2NaBr + Na2CO3 + 2H2O CONH2 + Br2 + 4KOH → R-NH2 + 2KBr+ K2CO3 + 2H2O - **Hunsdiecker Reaction:** R-COOAg + Br2 → R-Br+ CO2 + Ag Br CCl4 Reflux - **Kolbe's Reaction:** ONa + CO2 → COO Na → H+ → COOH (Salicylic Acid) 4-Fatm 400K - **Reimer-Tiemann Reaction:** OH + CHCl3 → ONa → [ONCHCl] 2NaOH → CH(OH) + H2O CHO Dil. HCl CHO (Salicyldehyde) - **Rosenmund Reduction:** R-C-Cl + H2 → R-C-H + HCl Pd, BaSO4, S Boiling Xylene - **Sandmeyer Reaction:** N2Cl + HBr → CuBr → Br +KCN CuCN → CN - **Stephen Reduction:** R-C≡N + 2[H] + HCl → R-CH=NH.HCl Dry ether → RCHO + NH4Cl Boiling H2O - **Williamson Synthesis:** R-X + R'ONa → ROR' + NaX CH3-I + C2H5-ONa → CH3-O-C2H5 + NaI ether - **Wolff Kishner Reduction:** R-CHO → R-CH3 + N2 CH3COCH3 → CH3-CH2-CH3 -COCH3 → CH2CH3 HN-NH2, KOH glycol - **Wurtz Reaction:** R-X + 2 Na + X-R → R-R + 2NaX CH3-Br + 2 Na + Br-CH3 → C2H6 + 2 NaBr Dry ether - **Wurtz-Fittig Reaction:** CH3-Br + 2Na + Br → CH3 + 2 NaBr Dry ether Toluene ## #02. Resonance - **Positive Resonance:** - Positive resonance effect (+R effect) - Phenol - O-H - + - :O-H - 8-O-O- - - R effect showing groups: halogen, OH, OR, OCOR, NH, NHR, -NR2, -NHCOR - **Negative Resonance:** - Negative resonance effect (-R effect) in nitrobenzene - O2N - N - ↔↔ - + - N - ↔↔ - + - - - - - O2N - R effect showing groups: -COOH -CHO C=O, -CN -NO2 - **These are ortho and para directing** - **These are meta-directing** ## Road Map #01 (Diazonium Salt) - R-H + H2O/109°m → R-OH - H3PO2 - Phenol - R-H + H2SO4 → Benzene - R-H + Cu/HCl → Chloro benzene - R-H + Cu/HBr → Bromo benzene - R-H + CuCN→ Benzonitrile - R-H + KI → Iodobenzene - R-H + HBF4, ∆ → Fluoro benzene - R-H + NaNO2/KSU → Thiophenol - (R-NH2, OH) → N2+ → Azo Dye - Coupling Rxn - Gattermann Rxn - Balz Schiemann Rxn ## Aromatic Conversions - Biphenyl Sn/HCl → NO2 Nitrobenzene - NH2 - Aviline - HNO3, H2SO4 - KNH3, C2O - 2Na Dry ether - Fitting Rxn - H2SO4 → SO3H Benzene - CH3COCl - Anhy AlCl3 - Benzene - CH3 - Toluene - Zn, Hg → CH2CH3 - HCl - NaNO2, H2O - 623 K - 300 Alu → OH Phenol ## Road Map #03 - Biphenyl → 2Na → Cl → CH3, 2Na → CH3 Toluene - (i) NaNO2 623K - (ii) H2O 300°C - Chloro benzene - CUCN → CN - CH3 - [O] → COOH - Soda - lime → C6H6 Benzene - Benzoic Acid - [O] - OH - Phenol - H2, H2O → COO - Benzoic Acid - H2O/OH → Benzyl - Chloride - [O] → CHO Benzaldehyde - CONH2 → Benzyl alcohol - Benzamide ## #04. Test To Distinguish - **How will you distinguish b/w propanol and propanone** - Iodoform Test: - Propanol: C3H7OH + I2 + NaOH → No Rxn - Propanone: CH3COCH3 + I2 + NaOH → CHI3 + CH3COONa + H2O + NaI - Yellow ppt. - **How will you distinguish b/w ethanol and phenol** - Litmus Test: - Ethanol: Doesn't give litmus test. - Phenol: Turn blue litmus into red. - Iodoform Test: - Ethanol: C2H5OH + I2 + NaOH → CHI3 + HCOONa + NaI + H2O - Phenol: OH + I2 + NaOH → No Rxn - Br2, water test: - Ethanol: C2H5OH +Br2 → No white ppt - Phenol: OH + 3Br2 → Br → Br → Br - **How will you distinguish b/w ethanal and propanal** - Iodoform test: - Ethanal: CH3CHO + I2 + NaOH → CHI3 + HCOONa + 3NaI + 3 H2O - Propanal: C3H7CHO + I2 + NaOH → No yellow ppt. - **Distinguish b/w Pentan-2-one & Pentan-3-one** - Iodoform test: - CH3COCH2CH2CH3 + I2 + NaOH → CHI3 + CH3COONa + H2O + NaI - CH3CH2COCH2CH3 + I2 + NaOH → No Yellow ppt. & CHI3 - **How will you distinguish b/w propanal & propanone** - Iodoform test: - Propanal: CH3CH2CHO + I2 + NaOH → No Yellow ppt. - Propanone: CH3COCH3 + I2 + NaOH → CHI3 + CH3COONa + H2O + NaI - Tollen's Reagent test: - Propanal: CH3CH2CHO + 2Ag(NH3)2+ → CH3CH2COO- + 2Ag + 4NH3 + 2H2O (Silver mirror) - Propanone: CH3COCH3 + Tollen's Reagent → No silver mirror - Fehling Solan test: - Propanal: CH3CH2CHO + 2(Cu2+ + SO42- → CH3CH2COO- + Cu2O + 3H2O - Propanone: CH3COCH3 + Fehling Solan Test → No Red Ppt. - **Distinguish b/w Benzaldehyde (C6H5CHO) & Acetophenone (C6H5COCH3)** - Iodoform test: - Benzaldehyde: CHO + NaOH + I2 → No yellow ppt - Acetophenone: COCH3 + NaOH + I2 → CHI3 + COONa + H2O + NaI - AgNO3 test: - Benzaldehyde: CHO → Tollen's Reagent → Giver Silver mirror - Acetophenone: COCH3 → Tollen's Reagent → No Silver mirror - **Acetophenone (C6H5COCH3) and benzophenone ( C6H5CO C6H5)** - Iodoform Test: - Acetophenone: COCH3 + I2 + NaOH → CHI3 + H2O + COONa - Benzophenone: CO-CO + I2 + NaOH → No yellow ppt of CHI3 - **Methanoic Acid (HCOOH) and Ethanoic Acid (CH3COOH)** - Tollen's Test: - Methanoic Acid: HCOOH + 2[Ag(NH3)2]+ + 2OH- → 2Ag+ + CO2 + 2 H2O + 4NH3 - Ethanoic Acid: CH3COOH + Tollen's Reagent → No Silver Mimr ## Benzoic Acid (COOH) and Phenol (OH) - **NaHCO3 Test:** - Benzoic Acid: COOH + NaHCO3 → CooNa + (H+) -THO - Phenol: OH + NaHCO3 → No evolution of CO2 - **FeCl3 Test:** - Benzoic Acid: 3(COOH) + FeCl3 → 3(COO)- + Fe3+ + 3HCl - Phenol: OH + FeCl3 → Violet coloration - Buff (Colored ppt.) ## Methylamine (CH3NH2) and dimethylamine (CH3NHCH3) - **Carbyl Amine Test:** - Methylamine: CH3NH2 + CHCl3 + 3KOH → CH3NC + 3KCl + 3H2O - Dimethylamine: CH3NHCH3 + CHCl3 + 3KOH → No Rxn - **Hinsberg Reagent:** - Methylamine: CH3NH2 + SO2. Hinsberg Reagent - SO2-NHCH3 + KOH → SO-N-(CH3)K+ + H2O - soluble in KOH - Dimethylamine: CH3NHCH3 + SO2. - SO2-N-CH3 - insoluble in aq KOH ## Ques Related to Physical Properties - **b-dichlorobenzene has higher m.pt than that of ortho and meta isomers.** - p-dichloro benzene has higher m.pt than those of o- and m-isomers because it is more symmetrical and packing is better in Solid form. Hence it has stronger inter molecular force of attraction than o. and m-isomers. - **Alkyl halides though polar are immiscible with water?** - Alkyl halides are polar but are insoluble in water because energy required to break the intermolecular H-bonding among water molecules is much higher than energy released by water halide interaction. - **Why the dipole moment of chlorobenzene is lower than cyclohexane?** - In Chlorobenzene C-Cl bond has some double bond character so its bond length is smaller Hence dipole moment is smaller than cyclohexyl chloride which has a longer C-Cl single bond. - **Solubility of Alcohols:** - Solubility of alcohols is water is due to their ability to form hydrogen bond with water molecules. The solubility decreases with increase in size of alkyl groups and solubility increases with increase in branching the order is 1°<2°<3°. - **Boiling point of Alcohols:** - The B.pt of alcohol increases with increase in no. of carbon atoms as van der waal forces increases and b.pt decreases with increase in branching of carbon chain due to decrease in van der waal forces. with decrease in surface area and the order is 1°>2°>3°. - **Acidity of Alcohols:** - The acid strength of alcohols decrease in order RCH2OH > R2CHOH > R3COH - **Solubility of Ethers:** - Ethers are soluble in water to certain extent due to H-Bonding - Solubility decreases with increase in mol. mass - Ethers are fairly soluble in all organic solvents such as chloroform, alcohol, benzene ek. - **Solubility of Phenols:** - Like alcohols, phenols are soluble in water due the formation of H-bonding with water. - Phenols are less soluble than alcohols due to large hydrocarbon (benzene ring) bart. -Phenols are soluble in alcohols, ethers and also in NaOH. - **Boiling Point:** - Much higher than corresponding hydrocarbons and haloarenes due to intermolecular H-Bonding. - **Boiling Point of Aldehydes and Ketones:** - The B.pt of aldehydes and Ketones are higher than hydrocarbons and ethers d Comparable molecular mass due to weak dipole -dipole interaction. -Their bipt are lower than those of alcohols of similar molecular mass due to absence of intermolecalar H-Bond. -Among isomeric aldehydes and ketones, tectones have slightly higher B.Pt due to the presence of two releasing gp which make carbonyl group more polar. - **Solubility of aldehydes and Ketones:** - Lower members of aldehydes and Ketones cabo ((4) are soluble in water due to H. Bonding blw Polar carbonyl group and water. However, solubility decreases with increase in mol. str. - Aromatic aldehydes and ketones are much less than corresponding aliphatic aldehydes and ketones due to larger benzene ring. - All carbonyl compounds are fairly soluble in organic Solventi. - **Solubility of Carboxylic Acid:** - Simple aliphatic carboxylic acids having upto (4 atoms are miscible in water due to formation of H. Bond with water. - The solubility decreases with increasing no. of Carbon atoms. Higher carboxylic acids are practically insoluble in water due to the increased hydrophobic interaction of hydrocarbon part. - Benzoic acid, the simplest aromatic carboxylic acid is nearly insoluble in cold water. - **Boiling Point of Carboxylic Acid:** - Carboxylic acids have higher Bet than aldehydes, ketones and eyen of comparable molecular mass due to more extensive association of their molecules through inter molecular H-Bonding. The H-Bonds are not broken completely even in their Vapour Phase. - **Boiling Point and Solubility of Amines:** - 1° and 2º amines have higher B.Pt than other organic compounds due to Hydrogen bonding. - Primary and secondary amines are soluble in water due to H-Bonding b/w >NH2 & H2O molecules. ## # ACIDIC AND BASIC CHARACTER - **Basic Character of Amines:** - Amines are basic in nature due to the presence of lone pair of eo on nitrogen atom - Aliphatic amines are stronger bases than ammonia due to +I effect of alkyl group present in Amines. - Aromatic amines are weaker bases than ammonia due to -I effect of aryl, group. - Besides inductive effect there are effects like steric effect, solvation effect, resonance eftect which affect the basic strength of amines. - In gaseous phase, the order of basicity 3o amines > 2o amines > 1o amines > NH3 - **In aqueous phase, despite of inductive eftect, solvation eftect and steric hindrance also plays an important rule. Thus, the orde of basicity of amines is** - (C2H5)2NH > (C2H5)3N > C2H5 NH2 > NH3 - (CH3), (CH3)2NH > CH3NH2 > (CH3)3N > NH3 - Aryl groups are more acidic than alkyl groups. ## # ORGANIC REAGANTS AND REATIONS - **Reducing Agents:** - Preparation of Alcohols by Reduction of Carbonyl Compounds: - **Reagent:** Transformation - **Alcohol** PCC Aldehyde - **Alcohol** CrO3/pyridine - **Alcohol** [H] Ketone - **Alcohol** [H] Acid - **Aldehyde** [H] Ketone - **Ester** LIAIH4 - **Ester** NaBH4 - **Ester** Raney Ni/Pd/C - **Ester** DIBAL-H - **Acid Chloride** [H] - **Acid Chloride** [H] - **Aldehyde** PCC - **Ketone** CrO3/pyridine - **Aldehyde** H2CrO4 - **Ketone** KMnO4 - **Alcohol** H2O2 - **Alcohol** KMnO4 - **Alcohol** HCrO4 - **Alkane** KMnO4 - **Alkene** O3. then Zn Aldehyde/Ketone - **Alkene** O3. then CH3SCH3 - **Name of Reagent** **Conditions** **Example of its Use** - K2Cr2O7 with warm gently Oxidising agent, used commonly for oxidising secondary alcohols to ketones. conc. H2SO4 - Excess conc. Heat to 170 C Dehydrating agent, used to dehydrate alcohols to alkenes. H2SO4 - Cl2(g) Ultra Violet light Free radical reaction, used to convert alkanes to haloalkanes. - Br2 in CCl4 Room temperature, Electrophilic addition, converts alkenes to dihaloalkanes. in the dark - H2(g) Nickel catalyst, 300°C Hydrogenating agent, used to convert benzene to cylcohexane. - H2(g) Nickel catalyst, 150 Reducing agent for converting - Tin in atmospheres nitrobenzene to phenylamine. hydrochloric acid - C Reflux Reducing agent used to convert NaOH in ethanol alkenes to alkanes - Acidified KMnO4 Room temperature Oxidising agent, converts alkenes to diols. - KOH Reflux Elimination reaction, converts haloalkanes to alkenes. - **Oxidising Agents:** - **Reagent:** Transformation - *PCC Alcohol Aldehyde* - *CrO3/pyridine Alcohol Aldehyde* - *H2CrO4 Aldehyde Carboxylic acid* - *KMnO4 Aldehyde Carboxylic acid* - *H2O2 Alcohol Carboxylic acid* - *KMnO4 Alcohol Carboxylic acid* - *HCrO4 Alcohol Carboxylic acid* - *KMnO4 Alkane Carboxylic acid* - *O3. then Zn Alkene Aldehyde/Ketone* - *O3. then CH3SCH3 Alkene Aldehyde/Ketone* - **Aqueous NaOH** Reflux Nucleophilic substitution, converts haloalkanes to alcohols. - **Mg in dry ether** Reflux Used to make grignard reagents with haloalkanes. - **PCl5** Room temperature Chlorinating agent, reacts with OH group in alcohols and carboxyllic acids - **HNO3 and H2SO4** 55°C Adds NO2 group onto benzene ring. - **Cl2 and AlCl3** Warm gently Adds Cl group onto benzene ring. - **CH3CH2Cl and Warm gently Adds CH2CH2 group onto benzene AlCl3 ring. - **HCl and NaNO2** Below 5°C Forms diazonium salts with phenylamine. ## # ORGANIC REACTION MECHANISMS - **Nucleophilic Substitution Reaction:** - **Comparing the SN1 and the SN2 reactions** - | | SN1 | SN2 | -|--------------------|-----------------------------------------|---------------------------------------------------------| | Rate Law | Unimolecular (substrate only) | Bimolecular (substrate and nucleophile) | | "Big Barrier" | Carbocation stability | Steric hindrance | | Alkyl halide | 3°>2°>>1° (worst) | 1°>2°>>3° (worst) | | (electrophile) | | | | Nucleophile | Weak (generally neutral) | Strong (generally bearing a negative charge) | | Solvent | Polar protic (e.g alcohols) | Polar aprotic (e.g. DMSO, acetone) | | Stereochemistry | Mix of retention and inversion | Inversion only | - **SN1 Mech:** - Unimolecular Nucleophilic Substitution Rxn - The rate of reaction depends only on the conc. of reactant i-e alkyl halide - eg order of reaction = 1 - molecularity of reaction = 1 - This reaction takes place in two steps. - СH₃ - | - CH CH3 X + OH- → CH3C+-OH + X- - | - CH3 - SN1 Mechanism - Nucleophile - CH3 CH3 - | - CH3C + X- - | - CH3 - - Step-1 formation of intermediate carbocation - CH3 CH3 - | - CH3C+ + X- - | - CH3 - Halide fon - Step-II - Attack of nucleophile on C+ may occur either from front side or from backside - CH3 CH3 - | - CH3C - OH + OH- - | - CH3 - CH3 CH3 - | - CH3C-OH + OH- → CH3 - | - CH3 - Rate of Rxn = K[(CH3)3C-X] - Order 1. - - **SN2 mech:** - Order= 2 - molecularity=2 - because the rate of reaction depends upon the conc. of both reactants i-e alleyl halide and Nucleophile - ex: Substitution by hydroxy group. - R-X + OH- → R-OH + X - Leaving Group. - SN2 Mechanism - Nucleophile - CH3 CH3 - | - CH3C-OH + X- - | - CH3 - Rate of Rxn = K[(CH3)2CH-X][OH-] --- - In this mechanism, the configuration of alkyl halide gets Inverted. This is called inversion of configuration or Walden inversion. - **Acid Catalysed Hydration of Alkenes:** - *Acid Catalysed Hydration* - (a) In Symmetrical Alkenes - (b) In Unsymmetrical Alkenes - *#Mechanism* - (a) CH3=CH2 + H2O - (b) CH3-CH=CH2 - CH3-C-CH3 + H2O | - CH3 - (H+) - (H+) - (H+) - (H+) - CH2-CH2-OH - CH3-C-CH3 + O=C-H - | - CH3 - CH3-C-CH3 + H2O (Hydronium ion) - | - CH3 - CH3-CH-CH3 + H2O (Alcoho - | - OH - CH3-C=CH2 + H2O - | - CH3 - H2SO4 - CH3-C-CH3 + H2O - | - CH3 - H+ + H2O (Hydronium ion) - **Dehydration of Alcohol** - Dehydration of Alcohol - *#Mechanism of Dehydration of alcohol* - Step-1 - CH3-CH2-CH2-C-OH + (H+) → CH3-CH2-CH2-C+H2O - | • "(fast) - CH3 - Step-2 - CH3-CH2-CH2-C+H2O → RDS CH2=CH2 +H+ - | - CH3 - Order of Dehydration: 3°>2°>1° - **Ethers:** - Preparation of Ethers - *(*) Dehydration of Alcohol* - CH3-CH2OH + H2SO4 → CH2=CH2 + elimination - 443K - 2(CH3-CH2-OH) → CH3-CH2-O-CH2-CH3 - 443K - (i) Low temperature (+) - (ii) Less hindered alcohol (+) - (iii) SN² mechanism is followed - (iv) High concentration of alcohol is used - CH3-CH2-O-H + H + → CH3-CH2 + H2O - | - CH3-CH2-O- + CH3-CH2-OH → CH3-CH2-O-CH2-CH3 - Nu - C - O - | - | - Nu - Slow step - C - Tetrahedral Intermediale - | - H+ - + - | - Nu - Fast step - C - OH - | - Addition Product ## # BIOMOLECULES - **CARBOHYDRATES:** - These are optically active polyhydroxy aldehydes or Ketones - General formula: Cx(H2O)y - **CLASSIFICATION ON THE BASIS OF

Class 12 Organic Chemistry Cheat Sheet PDF

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