Naphthalene C10H8 is an organic compound having the simplest polycyclic aromatic hydrocarbon. It is a white crystalline solid with a characteristic odour. Naphthalene’s structure consists of a fused pair of benzene rings. It is best known as the main ingredient of traditional mothballs. It can be synthesized by Haworth synthesis, the steps are as follows:
- The Friedel craft acylation reaction of benzene with succinic anhydride gives 3 benzoylpropionic acid.
- Second step is the Clemmenson’s reaction with 3-benzoylpropionic acid which gives 4-phenylebutanoic acid.
- On heating this product in the presence of concentrated sulphuric acid results in the formation of ring structure of α-tetralene by the ellimination of water molecule.
- The Clemmenson reaction of α-tetralene gives tetrahydronaphthalene.
- Dehydrogenation of tetrahydronaphthalene in the presence of selenium yields naphthalene.