New bis:amino-thiazoldi:yl squaric acid betaine dyestuff cpds. - having intense long wave absorption, useful e.g. in information recording and laser technology

摘要

New 2,4-bis(N,N-di-substd. 2-amino-thiazol-5,5-diyl)-squaric acid betaine dyestuffs are of formula (I): R1-2 = linear 1-6C alkyl, substd. alkyl, aralkyl or an opt. substd. phenyl or naphthyl gp.; or NR1-2 = an aliphatic ring opt. contg. other hetero-atoms, e.g. pyrroloidino, piperidino or morpholino; R3 = H, (substd.) phenyl, naphthyl, 1-6C alkyl, CN, COOR, OH, halogen or heteroaryl, e.g. thienyl or indenyl; R = 1-6C alkyl. USE/ADVANTAGE - (I) can be synthesised easily. They have intensive absorption in the long wavelength region of the spectrum, which can be varied in a wide range of substits., and are hardly soluble in many organic solvents, making them suitable for a wide range of applications, esp. in information recording and laser technology. They also have high m.pt. and good light fastness in soln.. In an example, a mixt. of 111mg (1 mmole) (III), 712 mg (2 mmole) 2-N,N-dibenzylamino-4-phenyl-thiazole and 25 ml (IV) (12.5 ml 1-BUOH + 12.5 ml toluene) was boiled for 4 h, when the crude dyestuff crystallised out. After cooling to room temp., the prod. was filtered off and dried, giving 250 mg 2,4-bis (N,N-dibenzylamino -4-phenyl-thiazol -5,5-diyl)-squaric acid betaine as blue-green needles, m.pt. 253-255 deg.C.(recrystallised from ether and washed with MeOH); absorption max. = 687 nm (CHCl3).