Preparation of some new red fluorescent 4-cyanocoumarin dyes☆

摘要: Abstract The first fluorescent dyestuffs for polyester fibres appeared towards the end of 1960 s. These were coumarin derivatives, shades which, however, remained restricted to greenish yellow region. Thus, it was repeatedly attempted synthesise further disperse dyes possessing longer wavelength absorptions. introduction a cyano group into 4 -position ring offers surprisingly simple possibility achieving desired effect. new are formed readily and in high yield. They may be used dye brilliant red shades, exhibiting strong fluorescence. scope limitations reaction discussed compared with similar reactions reported literature.