More Conversions of Organic Compounds (NEET Chemistry)

How will you bring about the following conversions?

(1) Ethanol to but-1-yne

(2) Ethane to bromoethene

(3) Propene to 1-nitropropane

(4) Toluene to benzyl alcohol

(5) Propene to propyne

(6) Ethanol to ethyl fluoride

(7) Bromoethane to propanone

(8) But-1-ene to but-2-ene

(9) 1-chlorobutane to n-octane

(10) Benzene to biphenyl

Hint: In the question provided, various named reactions are involved, such as the Wurtz reaction, Swarts reaction, and Wurtz-Fittig reaction. Additionally, Markovnikov’s rule is applied during the bromination process with hydrogen bromide.

Complete step by step answer:

(1) Ethanol to but-1-yne formula

Ethanol to but-1-yne
$C H_{3} - C H_{2} - O H + S O C l_{2} \overset{P y r i d i n e}{\to} C H_{3} - C H_{2} - C l + S O_{2} + H C l$
$C H \equiv C H + N a N H_{2} \overset{L i q . N H_{3}}{\to} C H \equiv C^{-} N a^{+}$
$C H_{3} - C H_{2} - C l + C H \equiv C^{-} N a^{+} \to C H_{3} - C H_{2} - C \equiv C H + N a C l$
Ethanol is transformed into but-1-yne by initially reacting it with thionyl chloride in the presence of pyridine, producing chloroethane, sulfur dioxide, and hydrogen chloride. Next, chloroethane is reacted with the sodium salt of ethyne, yielding but-1-yne and sodium chloride. The sodium salt of ethyne is prepared by treating ethyne with sodium amide.

(2) Ethane to bromoethene form $C H_{3} - C H_{3} + B r_{2} \overset{U . V l i g h t}{\to} C H_{3} - C H_{2} - B r \overset{a l c . K O H}{\to} C H_{2} = C H_{2} \overset{B r_{2}}{\to} B r - C H_{2} - C H_{2} - B r \overset{a l c . K O H}{\to} C H_{2} = C H B r$
Ethane is converted to bromoethene by first reacting ethane with bromine in presence of U.V light to form bromoethane. Then bromoethane is reacted with alcoholic potassium hydroxide to form ethene. Ethene is then treated with bromine to form dibromoethane and on reacting with alcoholic potassium hydroxide forms bromoethene.

(3) Propene to 1-nitropropane formula

$C H_{3} - C H = C H_{2} + H B r \overset{P e r o x i d e}{\to} C H_{3} - C H_{2} - C H_{2} B r \overset{A g N O_{2}}{\to} C H_{3} - C H_{2} - C H_{2} N O_{2} + A g B r$
Propene is converted to 1-nitropropane by first reacting propene with hydrogen bromide in presence of peroxide to form 1-bromopropane which on reacting with silver nitrite forms 1-nitropropane and silver bromide.

(4) Toluene to benzyl alcohol formula

$C_{6} H_{5} - C H_{3} + C l_{2} \overset{U . V l i g h t}{\to} C_{6} H_{5} - C H_{2} C l \overset{N a O H}{\to} C_{6} H_{5} - C H_{2} O H + N a C l$
Toluene is converted to

Toluene is converted to benzyl alcohol by first reacting toluene with chlorine in presence of U.V light to form benzene methyl chloride which on reacting with sodium hydroxide to form benzyl alcohol and sodium chloride.

(5) Propene to propyne formula

$C H_{3} - C H = C H_{2} + B r_{2} \overset{C C l_{4}}{\to} C H_{3} - C H (B r) - C H_{2} (B r) \to_{L i q . N H_{3}}^{N a N H_{2}} C H_{3} - C \equiv C H$
Propene is converted to

Propene is converted to propyne by reacting carbon tetrachloride to form 1, 2-dibromopropane which reacts with sodium amide and liquid ammonia to form propyne.

(6) Ethanol to ethyl fluoride formula

$C H_{3} - C H_{2} O H + H C l \overset{Z n C l_{2}}{\to} C H_{3} - C H_{2} - C l + H_{2} O$
$C H_{3} - C H_{2} - C l + A g F \to C H_{3} - C H_{2} - F$
Ethanol is converted to ethyl fluoride by first reacting ethanol with hydrochloric acid in presence of zinc chloride to form chloroethane and water. Chloroethane is then reacted with silver fluoride to form ethyl fluoride.

(7) Bromomethane to propanone formula

$C H_{3} - B r \overset{K C N}{\to} C H_{3} - C N \overset{C H_{3} - M g - B r}{\to} C H_{3} - C C H_{3} = N M g B r \overset{h y d r o l y s i s}{\to} C H_{3} - C O - C H_{3}$
Bromomethane is converted to propanone by first reacting bromoethane with potassium cyanide which on reacting with methyl magnesium bromide to form an intermediate which on hydrolysis forms propanone.

(8) But-1-ene to but-2-ene formula

$C H_{3} - C H_{2} - C H = C H_{2} \overset{H B r}{\to} C H_{3} - C H_{2} - C H (B r) - C H_{3} \overset{a l c . K O H}{\to} C H_{3} - C H = C H - C H_{3}$

But-1-ene is converted to but-2-ene by first reacting but-1-ene with hydrogen bromide to form 2-bromo-butane which on reacting with alcoholic potassium hydroxide to form but-2-ene.

(9) 1-chlorobutane to n-octane formula

$2 C H_{3} - C H_{2} - C H_{2} - C H_{2} - C l + 2 N a \overset{d r y e t h e r}{\to} C H_{3} - (C H_{2})_{6} - C H_{3} + 2 N a C l$

1-chlorobutane is converted to n-octane by reacting 1-chlorobutane with sodium in presence of dry ether to form n-octane.

(10) Benzene to biphenyl formula

$C_{6} H_{6} + B r_{2} \overset{F e}{\to} C_{6} H_{5} - B r$
$2 C_{6} H_{5} - B r + 2 N a \overset{d r y e t h e r}{\to} C_{6} H_{5} - C_{6} H_{5} + 2 N a B r$
Benzene is converted to biphenyl by first reacting benzene with bromine in presence of iron to form bromobenzene. Bromo benzene is then reacted with sodium in presence of dry ether to form biphenyl and sodium bromide.

Note:

Ensure that alcoholic potassium hydroxide is utilized, as using aqueous potassium hydroxide will result in the formation of alcohol rather than alkene.

More Conversions of Organic Compounds (NEET Chemistry)

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