Question

What carboxylic acid and reagents need to prepare (a)N,N,2-trimethylpropanamide (b)Ethyl benzoate and (c)propanoyl chloride ?

Answer 1

You need (a) 2-methylpropanoic acid, (b) benzoic acid, and (c) propanoic acid.

Explanation:

(a) Preparation of N,N,2-trimethylpropanide

Convert 2-methylpropanoic acid to 2-methylpropanoic acid with `"PCl"_5`, then react it with dimethylamine.

`("CH"_3)_2"CHCOOH" stackrelcolor(blue)("PCl"_5 color(white)(m))(→) ("CH"_3)_2"CHCOCl" stackrelcolor(blue)("HN"("CH"_3)_2color(white)(m) )(→) ("CH"_3)_2"CHCON"("CH"_3)_2`

(b) Preparation of ethyl benzoate

Heat benzoic acid with ethanol and sulfuric acid as catalyst.

`"C"_6"H"_5"COOH"stackrelcolor(blue)( "CH"_3"CH"_2"OH"color(white)(m))(→) "C"_6"H"_5"COOCH"_2"CH"_3`
`color(white)(mmmmmmm)stackrelcolor(blue)(Δ, "H"_2"SO"_4)(color(white)(m)`

(c) Preparation of propanoyl chloride

Use `"PCl"_5` to convert propanoic acid to propanoyl chloride.

`"CH"_3"CH"_2"COOH" stackrelcolor(blue)("PCl"_5 color(white)(m))(→) "CH"_3"CH"_2"COCl"`