Synthesis and spectral properties of phthalimide based alkali-clearable azo disperse dyes

Abstract

The synthesis of a series of phthalimide based azo disperse dyes and their spectral properties were investigated. The azo dyes containing phthalimide and N-methyl phthalimide structure in diazo component were synthesized in order to compare their spectral properties. The synthesized dyes developed the color of yellow to violet and the N-substitution of the phthalimide gave a bathochromic effect on the color change. Most of the synthesized dyes exhibit negative solvatochromism so that the absorption band of dyes moves toward shorter wavelengths as the polarity of the solvent increases. In the case of halochromic effect, the bathochromic shift decreased steadily with the general electron donating capacity of the substituents in the coupling component, and became negative especially when more powerful electron donating groups are present in the coupling components ring.

Investigation of alkaline hydrolysis of phthalimide‐based azo dye and its application to after‐treatment optimisation for high‐fastness dyeing of polyesters

“…The syntheses of 4‐nitrophthalimide ( 2 ), N ‐methyl‐4‐nitrophthalimide ( 3 ) and 4‐amino‐ N ‐methylphthalimide ( 4 ) have been described previously .…”

“…After 4–5 h, the precipitated dye ( 5 ) was filtered, washed with water and dried. The dye was purified via recrystallization from methanol giving a red powder ; yield: 75.2%; purity: 99.87% (HPLC, acetonitrile/water = 80:20); mp: 187.3 °C; UV–vis [dimethylformamide (DMF)] λ max : 489 nm; ε max : 34 100; 1 H‐NMR [d 6 ‐dimethyl sulfoxide (DMSO)]: δ = 1.16 (t, 6H, 2 × CH 3 ), 3.46 (q, 4H, 2 × NCH 2 ), 3.05 (s, 3H, NCH 3 ), 6.83–6.85 (d, 2H, ArH), 7.82–7.85 (d, 2H, ArH), 7.95–7.97 (d, 1H, ArH), 8.02 (s, 1H, ArH), 8.09–8.11 (d, 1H, ArH) ppm. MS, m/z (M + ): 337.…”

Dyeing and fastness properties of phthalimide‐based alkali‐clearable azo disperse dyes on poly(ethylene terephthalate)

“…The synthesis of the phthalimide‐based azo disperse dyes used was carried out as described in a previous study [8]. The synthesised dyes ( P1 – P5 and MP1 – MP5 ) that were used throughout the study are listed in Table 1.…”

“…The colour gamut of phthalimide‐based 4‐( N , N ‐diethylamino)azobenzene dyes that were synthesised previously [4], was orange to red [478–490 nm in dimethyl formamide (DMF)]. More recently, a larger range of colours, from yellow to violet, has been synthesised [8]. Hydroxypyridone derivatives were used as coupling components because they provide greenish‐yellow to orange shades and have significantly high tinctorial strength [9].…”

Methanol-Assisted Phthalimide Ring Opening: Concerted or Stepwise Mechanism?

“…Phthalimide and its derivatives are the precursors of anthranilic acids, which are widely used to synthesize useful organic compounds like azo dyes and saccharins. − They have also been used to synthesize pharmaceutical molecules containing benzamides. − Recently, Piou and Rovis have developed an elegant reaction methodology with N -enoxyphthalimides for the syn -carboamination of alkenes, in which N -enoxyphthalimides serve as the source of both C and N functionality and the Rh­(III) complexes serve as the catalysts . Reportedly, the use of methanol as the solvent is critical to improve the efficiency of this carboamination reaction …”