Question: Show how you can synthesize the following compounds starting with benzene, toluene, and alcohols containing no more than four carbon atoms as your organic starting materials. Assume that para is the major product (and separable from ortho) in ortho, para mixtures.

(a) pentan-1-amine

(b) N-methylbutan-1-amine

(c) N-ethyl-N-propylbutan-2-amine

(d) N-benzylpropan-1-amine

(e)

(f) 3-propylaniline

(g) 4-isobutylaniline

(a) Butan-1-ol reacts with tosyl chloride in presence of pyridine to give the initial product as butyl 4-methylbenzenesulfonate. Again, butyl 4-methylbenzenesulfonate reacts with potassium cyanide to give pentanenitrile, which on further reduction with lithium aluminum hydride gives the final product as pentan-1-amine.

reaction a
(b) Butan-1-ol is oxidized to butyraldehyde by PCC (pyridinium chlorochromate). Again, butyraldehyde reacts with methylamine to give (E)-N-butylidenemethanamine, which on further reduction with NaBH(OAc)₃ (sodium triacetoxy borohydride)gives the final product as N-methylbutan-1-amine.

reaction b

(c) Butan-2-ol is oxidized to butan-2-one by PCC (pyridinium chlorochromate). Again, butan-2-one reacts with propan-1-amine to give (E)-N-(butan-2-ylidene)propan-1-amine, which on further reduction with NaBH(OAc)₃ (sodium triacetoxy borohydride)gives N-propylbutan-2-amine. Also, N-propylbutan-2-amine reacts with acetaldehyde to form (E)-N-ethylidene-N-propylbutan-2-aminium. Lastly, on reduction with NaBH(OAc)₃ (sodium triacetoxy borohydride)gives the final product as N-ethyl-N-propylbutan-2-amine.


reaction c

(d) Toluene reacts wih N-bromosuccinimide to give (bromomethyl)benzene, which again reacts with excess ammonia to form phenylmethanamine. Again, propan-1-ol is oxidized to propionaldehyde by by PCC (pyridinium chlorochromate). Lastly, phenylmethanamine combines with propionaldehyde to form (E)-1-phenyl-N-propylidenemethanamine, which on further reduction with NaBH(OAc)₃ (sodium triacetoxy borohydride)gives the final product as N-benzylpropan-1-amine.

reaction d

(e) Benzene when treated with nitric acid in presence of sulfuric acid gives the initial product as nitrobenzene, which on further reduction with Sn/HCl gives aniline. Again, aniline on treatment with nitrous acid in presence of hydrochloric acid gives benzenediazonium chloride, which on further reaction with water gives phenol. Lastly, benzenediazonium chloride combines with phenol to give the final product as 4-(phenyldiazenyl)phenol.


reaction e

(f) Benzene when treated with nitric acid in presence of sulfuric acid gives the initial product as nitrobenzene, which on further reaction with propionyl chloride in presence of aluminum chloride forms 1-(3-nitrophenyl)propan-1-one. Lastly, 1-(3-nitrophenyl)propan-1-one on reduction with amalgamated zinc and hydrochloric acid gives the final product as 3-propylaniline.

reaction f

(g) Benzene when treated with nitric acid in presence of sulfuric acid gives the initial product as nitrobenzene, which on further reduction with Sn/HCl gives aniline. Again, aniline reacts with isobutyryl chloride in presence of aluminum chloride to form 1-(4-aminophenyl)-2-methylpropan-1-one. Lastly, 1-(4-aminophenyl)-2-methylpropan-1- one on reduction with amalgamated zinc and hydrochloric acid gives the final product as 4-isobutylaniline.


reaction g