ORGANIC CONVERSIONS

ORGANIC CONVERSIONS (text book) 1. Identify the A,B,C,D,E,R & R’ in the following: (i) Br + Mg dry Ether A H2O (ii) R—Br + Mg dry ether C D2O CH-CHD-CH3 R’—X Na/ ether (iv) R’—X Mg/ ether D H2O E 2. A hydrocarbon C5H10 does not react with chlorine in dark but gives a single monochloro compound C5H9Cl in bright sun light. Identify the hydro carbon. Ans: CH2=CH-CH2-CH-CH3 + Cl2 hv CH2=CH-CH2-CH-CH2-Cl 3. Write the equations for the preparation of 1-Iodo butane from : (i) 1 – butanol (ii) 1- chloro butane (iii) But-1-ene Ans: CH3-CH2-CH2-CH2-OH + HI or (P4+ I2 ) ( CH3-CH2-CH2-CH2-I CH3-CH2-CH2-CH2-Cl + NaI ( CH3-CH2-CH2-CH2-I CH3-CH2=CH2-CH3 + HI ( CH3-CH2-CH2-CH2-I 4. Predict the product from the following reactions: CH3 C2H5ONa Br Ethanol C2H5ONa CH3-CClCH3-CH2-CH3 Ethanol C2H5ONa Ethanol Br How will you bring about following conversions: Ethanol to but-1-yne Ethane to bromoethene Propene to 1-nitropropane Toluene to benzyl alcohol Propene to propyne Ethanol to ethyl fluoride Bromomethane to propanone But-1-ene to but-2-ene 1-Chlorobutane to n-octane Benzene to biphenyl. Propene to propan-1-ol Ethanol to but-1-yne 1-Bromopropane to 2-bromopropane Toluene to benzyl alcohol Benzene to 4-bromonitrobenzene (vi) Benzyl alcohol to 2-phenylethanoic acid Ethanol to propanenitrile Aniline to chlorobenzene 2-Chlorobutane to 3, 4-dimethylhexane 2-Methyl-1-propene to 2-chloro-2-methylpropane Ethyl chloride to propanoic acid But-1-ene to n-butyliodide 2-Chloropropane to 1-propanol Isopropyl alcohol to iodoform Chlorobenzene to p-nitrophenol 2-Bromopropane to 1-bromopropane Chloroethane to butane Benzene to diphenyl tert-Butyl bromide to isobutyl bromide Aniline to phenylisocyanide Phenol into o-nitro Phenol Phenol into Tri nitro phenol Propene → Propan-2-ol. Benzyl chloride → Benzyl alcohol. Ethyl magnesium chloride → Propan-1-ol. Methyl magnesium bromide → 2-Methylpropan-2-ol. Propanone to Propene Benzoic acid to Benzaldehyde (Ethanol to 3-Hydroxybutanal Benzene to m-Nitroacetophenone Benzaldehyde to Benzophenone Bromobenzene to 1-Phenylethanol Benzaldehyde to 3-Phenylpropan-1-ol Benazaldehyde to α-Hydroxyphenylacetic acid (ix) Benzoic acid to m- Nitrobenzyl alcohol Benzene into aniline (ii) Benzene into N, N-dimethylaniline Cl–(CH2)4–Cl into hexan-1,6-diamine? Ethanoic acid into methanamine Hexanenitrile into 1-aminopentane Methanol to ethanoic acid (iv) Ethanamine into methanamine Ethanoic acid into propanoic acid Methanamine into ethanamine Nitromethane into dimethylamine Propanoic acid into ethanoic acid? Nitrobenzene to benzoic acid Benzene to m-bromophenol Benzoic acid to aniline Aniline to 2,4,6-tribromofluorobenzene Benzyl chloride to 2-phenylethanamine Chlorobenzene to p-chloroaniline Aniline to p-bromoaniline Benzamide to toluene Aniline to benzyl alcohol. Some Important Conversions 2- Bromo Propane into 1 – Bromo Propane Propan-2-ol into Propan -1- ol Formaldehyde into Propan -1- ol Acetaldehyde into Propan -2-ol Acetone into t-Butyl alcohol Aneline into Phenol Cumene into Phenol Phenol into salicylic Acid Phenol into 2 – Acetoxy Benzoic Acid ( Aspirine) Propan -1-ol into 2-Bromo Propane Phenol into Benzaldehyde Phenol into Salcilaldehyde Ethano into diethyl ether Ethyl chloride into propanal Benzene into Benzaldehyde Acetic acid to acetaldehyde Acetic acid into acetone Acetonitrile into Benzo phenone Acetaldehyde into lactic acid Acetaldehyde into crotanaldehyde (But-2enal) Acetaldehyde into Butan-1-ol Acetaldehyde into But-2enoic acid Acetaldehyde into Butane2,4 diol Acetone into 4-methyl pent-3ene-2-one Benzene into Benzoic acid Benzoic acid into Aneline Chloro Benzene into Benzoic acid Benzyl alcohol into Phenyl ethanoic acid 3-nitro Bromo Benzene into 3-nitro Benzoic acid 4-methyl Acetophenone into terphthalic acid cyclo hexane into adipic acid Phthalic acid into phthalamide Acetic acid into Malonic acid Acetic Acid into Alanine Benzene into methyl Benzoate Benzene into m-nitro Benzoic acid Benzene into p-nitro Benzoic acid Benzene into Phynyl Acetic acid Benzene into p-nitro Benzaldehyde Benzene into Aneline Ethyl chloride to propanamine Ethyl amine into Ethyl Carbyl amine Aneline into 4-bromo Aneline Aneline into 4-Nitro Anelien Aneline into Sulphanilic acid Aneline into Acetanilide Phenol into Phenyl Acetate Aneline into Floro Benzene Aneline into Nitro Benzene Aneline into Phenol Aneline into Benzoic Acid Aneline into Benzene 4-Nitro Toluene into 2-Bromo Benzoic Acid 3-methyl Aneline into 3-Nitro Toluene Acetic Acid to Methanol Ethyl Bromide into Propan-1-ol Benzamide into Toluene Aneline into Benzyl alcohol Benzoic Acid into Aneline Benzene into m-bromo phenol Propanoic acid into Ethanoic acid Methanamine into Ethanamine Ethanoic Acid into Propanoic Acid Ethanamine into Methanamine Benzoic Acid into m-nitro Benzyl alcohol Benzaldehyde into alpha hydroxyl phenyl Acetic acid Benzaldehyde into 3-Phenyl Propan-1-ol Benzaldehyde into Benzophenone Benzene into m-nitro Acetophenone Propanone into Propene Ethyl Chloride into Propanoic acid Ethanol into Propanol Ethanol into Propanoic Acid Toluene into Benzyl alcohol Ethanol into But-1-yne Propene into Propyne CH3CH2I NaCN A Partial Hydrolysis B NaOH/Br2 C OH- Diazonium Chloride into Benzamide Ethyl Bromide into Propan-1-ol Acetic Acid into Methanol SOME WORD PROBLEMS 1.Write structural formulae of the organic compounds ‘A’,’B’,’C’and ’D’ in the following sequence of reactions: ‘A’ +CH3MgBr — H2O→ CH3CH2CH(OH)CH3 —conc H2SO4→ ‘B’ — Br2 → ‘C’ — alc.KOH→ ‘D’ 2. Etherical solution of an organic compound ‘A’ when heated with magnesium gave ‘B’. ‘B’ on treatment with wthanal followed by acid hydrolysis gave 2-propanol. Identify the compound ‘A’. what is ‘B’ known as? 3. A organic compound ‘A’ (molecular formula C3H6O) is resistant to oxidation but forms a compound ‘B’ (C3H8O) on reduction. ‘B’ reacts with HBr to form a bromide ‘C’ which on treatment with alcoholic KOH forms an alkene ‘D’ (C3H6). Deduce the structures of A,B,C and D. 4. A compound ‘A’ which has characteristic odour, on treatment with NaOH forms two compounds ‘B’ and ‘C’. compound ‘B’ has the molecular formula C7H8O which on oxidation gives back compound ‘A’. Compound ‘C’ is the sodium salt of an acid , ‘C’ when heated with soda lime yields an aromatic hydrocarbon ‘D’. Deduce the structures of A,B,C and D. 5. An organic compound ‘A’ has the molecular formula C5H10O. it does not reduce Fehling solution but forms a bisulphate compound. It also gives positive iodoform test. What are possible structures of ‘A’? 6. A compound ‘A’ with molecular formula C5H10 O gave a positive 2,4-DNP test but a negative Tollen,s test. It was oxidized to carboxylic acid ‘B’ with molecular formula C3H6O2. Sodium salt of ‘B’ gave a hydrocarbon ‘C’ on Kolbe’s electrolytic reduction. Identify A,B and C and write the chemical equations for the reaction. 7. When phenol heated with Zn it forms ‘A’. ‘A’ converts in to ‘B’ when reacts with conc.HNO3 in presence of sulphuric acid. ‘B’ converts in to ‘C’ when it reacts with Br2. ‘C’ converts into ‘E’ by hydrogenation followed by reaction with nitrous acid/HCl. Finally it converts into ‘F’ by acidic hydrolysis. Identify A,B,C,D,E and F. 8. An aliphatic compound ‘A’ with a molecular formula of C3H6O reacts with phenyl hydrazine to give compound ‘B’. Reaction of ‘A’ with I2 in alkaline medium on warming, gives a yellow ppt ‘C’. Identify compound A,B and C. 9. Two moles of organic compound ‘A’ on treatment with a strong base gives two compound B and C. Compound ‘B’ on hydrogenation with Cu gives ‘A’ while acidification of C yields carboxylic acid ‘D’, having molecular formula of CH2O2. identify the compounds A,B,C and D. 10. An organic compound ‘A’ having molecular formula C8H16O was hydrolysed with dilute sulphuric acid to give a carboxylic acid ‘B’ and an alcohol ‘C’. oxidation of ‘C’ with chromic acid produces ‘B’. Write IUPAC names for possible structures of ‘A’ and equations for the reactions involved. 11. A compound ‘A’ of molecular formula C3H7O2N on reaction with Fe and conc.HCl gives a compound ‘B’ of molecular formula C3H9N. compound ‘B’ on treatment with NaNO2 and HCl gives another compound ‘C’ of molecular formula C3H8O. Compound ‘C’ gives effervescence with Na. on oxidation with CrO3, the compound ‘C’ gives a saturated aldehyde containing three carbon atoms. Deduce the structures of A,B and C and write the equations for the reactions involved. 12. A compound ‘X’ having molecular formula C3H7NO, reacts with Br2 in presence of NaOH gives compound ‘X’. the compound ‘X’ reacts with HNO2 to form ethanol and N2 gas. Identify the compound X and Y and write the reactions involved. 13. An aliphatic compound ‘A’ with molecular formula C2H3Cl on treatment with AgCN gives two isomeric compounds of unequal amounts with the molecular formula C3H3N. The minor of these two products on complete reduction with H2 in the presence of Ni gives a compound ‘B’ with a molecular formula C3H9N. identify the compounds A,B and write the reactions involved. 14. Iodomethane reacts with KCN to form a major product ‘A’. Compound ‘A’ on reduction in presence of LiAlH4 forms a higher amine ‘B’. Compound B on treatment with CuCl2 forms a blue colour complex ’C’. Identify the compounds A,B and C. 15. An organic compound ‘A’ having molecular formula C2H3N on reduction gave another compound ‘B’. The Compound ‘B’ on treatment with HNO2 gave ethyl alcohol. ‘B’ on warming with CHCl3 and alcoholic potash gave an offensive smelling substance ‘C’. Identify A,B and C. 16. Two isomeric compounds A and B having molecular formula C4H11N, both loose N2 on treatment with HNO2 and gives compound C and D respectively. C is resistant to oxidation but immediately responds to Lucas reagent, whereas ‘D’ responds to Lucas reagent after 5 minutes and gives a positive iodoform test. Identify A and B. Primary alkyl halide C4H9Br (a) reacted with alcoholic KOH to give compound (b). Compound (b) is reacted with HBr to give (c) which is an isomer of (a). When (a) is reacted with sodium metal it gives compound (d), C8H18 which is different from the compound formed when n-butyl bromide is reacted with sodium. Give the structural formula of (a) and write the equations for all the reactions. An organic compound with the molecular formula C9H10O forms 2,4-DNP derivative, reduces Tollens’ reagent and undergoes Cannizzaro reaction. On vigorous oxidation, it gives 1,2-benzenedicarboxylic acid. Identify the compound. An organic compound (A) (molecular formula C8H16O2) was hydrolysed with dilute sulphuric acid to give a carboxylic acid (B) and an alcohol (C). Oxidation of (C) with chromic acid produced (B). (C) on dehydration gives but-1-ene. Write equations for the reactions involved. An organic compound contains 69.77% carbon, 11.63% hydrogen and rest oxygen. The molecular mass of the compound is 86. It does not reduce Tollens’ reagent but forms an addition compound with sodium hydrogensulphite and give positive iodoform test. On vigorous oxidation it gives ethanoic and propanoic acid. Write the possible structure of the compound. An aromatic compound ‘A’ on treatment with aqueous ammonia and heating forms compound ‘B’ which on heating with Br2 and KOH forms a compound ‘C’ of molecular formula C6H7N. Write the structures and IUPAC names of compounds A, B and C. *******