Question

How will you convert methane to the following: (a) propane (b) butane (c) methyl butanoate (d) ethanoic acid (e) ethanol?

Answer 1

Warning! Long Answer. Here are some possibilities.

Explanation:

(a) Propane

`"CH"_4 stackrelcolor(blue)("Cl"_2"/hν"color(white)(mm))(→) underbrace("CH"_3"-Cl")_color(red)("chloromethane")`

`"CH"_3"-Cl" stackrelcolor(blue)("Na/ether"color(white)(mm))(→) underbrace("CH"_3"-CH"_3)_color(red)("ethane")` (Wurtz synthesis)

`"CH"_3"-CH"_3 stackrelcolor(blue)("Cl"_2"/hν"color(white)(mm))(→) underbrace("CH"_3"CH"_2"-Cl")_color(red)("chloroethane")`

`"CH"_3"CH"_2"-Cl" stackrelcolor(blue)("Li/ether"color(white)(mm))(→) underbrace("CH"_3"CH"_2"-Li")_color(red)("ethyllithium")`

`"CH"_3"CH"_2"-Li" stackrelcolor(blue)("CuI"color(white)(mm))(→) underbrace(("CH"_3"CH"_2)_2"CuLi")_color(red)("lithium diethylcuprate")` (Corey-House synthesis)

`("CH"_3"CH"_2)_2"CuLi" + "CH"_3"-Cl" → underbrace("CH"_3"CH"_2"-CH"_3)_color(red)("propane")`

(b) Butane

`underbrace("CH"_3"CH"_2"-Cl")_color(red)("chloroethane") stackrelcolor(blue)("Na/ether"color(white)(mm))(→) underbrace("CH"_3"CH"_2"-CH"_2"CH"_3)_color(red)("butane")` (Wurtz synthesis)

(c) Methyl Butanoate

`underbrace("CH"_3"CH"_2"CH"_3)_color(red)("propane") stackrelcolor(blue)("Cl"_2"/hν"color(white)(mm))(→) underbrace("CH"_3"CH"_2"CH"_2"-Cl")_color(red)("1-chloropropane")`

`"CH"_3"CH"_2"CH"_2"-Cl" stackrelcolor(blue)("CN"^"-"color(white)(mm))(→) underbrace("CH"_3"CH"_2"CH"_2"-CN")_color(red)("1-butanenitrile")stackrelcolor(blue)(`

`"CH"_3"CH"_2"CH"_2"-CN" stackrelcolor(blue)("H"_3"O"^"+", Δcolor(white)(m))(→) underbrace("CH"_3"CH"_2"CH"_2"-COOH")_color(red)("butanoic acid")`

`underbrace("CH"_3"Cl")_color(red)("chloromethane") stackrelcolor(blue)("aq. KOH", Δ color(white)(mm))(→) underbrace("CH"_3"-OH")_color(red)("methanol")`

`"CH"_3"CH"_2"CH"_2"COOH" + "CH"_3"-OH" stackrelcolor(blue)("H"_3"O"^"+"color(white)(mm))(⇌) underbrace("CH"_3"CH"_2"CH"_2"CO-OCH"_3)_color(red)("methyl butanoate")`

(d) Ethanoic acid

`underbrace("CH"_3"-Cl")_color(red)("chloromethane") stackrelcolor(blue)("Mg/dry ether"color(white)(mm))(→) underbrace("CH"_3"-MgCl")_color(red)("methylmagnesium chloride")`

`"CH"_3"-MgCl" stackrelcolor(blue)("1. CO"_2; "2. H"^"+"color(white)(mm))(→) underbrace("CH"_3"-COOH")_color(red)("ethanoic acid")` (Grignard synthesis)

(e) Ethanol

`underbrace("CH"_3"CH"_2"-Cl")_color(red)("chloroethane") stackrelcolor(blue)("OH"^"-"color(white)(mm))(→) underbrace("CH"_3"CH"_2"-OH")_color(red)("ethanol")`