Benzyl ■ a - cyano cynnamic acid, a nitrile with active methylene group has been synthesized. The reaction of this compound with sulphur in the presence of diethylamine gave 2-Amino-4,5-dıphenyl-3-cyanothiophene. In addition, a similar compound, 2-amino 4-ethyl-5-methyl-3-cyanothiophene has been obtained from sulphur and malonic acid dinitrile using the same amine as catalyst. The both thiophenes and their Schiff’s bases with salicylaldehyde and [3-Hydroxynaphtaldehyde have been investigated by uv, ir and 'H-nmr spectroscopy and pKa measurements in terms of substituent and heteroatom effects on various characteristics.