The synthesis and characterisation of thiol-bearing C. I. Disperse Red 1

Abstract

C. I. Disperse Red 1 (DR1) was chemically modified by a facile, one-step, Steglich esterification to yield the thiol-bearing analogue. The dye produced possesses the appropriate functionality to be readily incorporated into appropriate materials by highly effective thiol-ene 'click' chemistry reactions. This method of dye modification greatly widens the application range of hydroxyl-bearing reactive dyes for various materials, enabling the facile production of coloured materials by using the thiol groups added.

Dye conjugation to linseed oil by highly-effective thiol-ene coupling and subsequent esterification reactions

“…The dye 4 had a maximum absorption wavelength ( max ) at 487 nm, while 5 had a  max at 476 nm. The hypsochromic shift of 11 nm in 4 following the chemical modification signified the successful conjugation of 3 and 4 [37,47]. This shift was not caused by solvatochromism, a mixture of 1 and 4 (with the same concentrations as 5) produced a similar spectroscopic curve ( max = 488 nm) to that of 4.…”

“…Esterification was then employed to graft DR1 to the functionalised linseed oil, yielding the desired product in a good, highly reproducible, yield. We have proposed the method of producing a thiolbearing DR1 via chemical modification of DR1, aiming to incorporate the dye into alkene-containing materials by TEC reactions [37]. The method we propose here offers the advantages of simpler reaction procedures and the need for less amount of dye compared to the previous method.…”

Antimicrobial Dye-Conjugated Polyglobalide-Based Organogels

“…DR1 3-mercaptopropionate ( 1 ) was synthesized, as reported previously . Briefly, DR1 (1.04 g, 3.30 mmol), 4-dimethylaminopyridine (DMAP) (3 mg, 0.03 mmol), and 3-mercaptopropionic acid (1.49 mL, 16.50 mmol) were mixed in anhydrous DCM (100 mL) and stirred at 0 °C under a N 2 flow.…”

“…18 For instance, thermosets that originate from plant oils and possess C=C double bonds may be permanently colored by a thiol-bearing reactive dye. Previous research within our group has disclosed both the modification of linseed oil by thiol-ene coupling to yield an oil that C. I. Disperse Red 1 (DR1) can be covalently attached to by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) coupling in water, 19 and the creation of thiol-bearing DR1, thereby converting a disperse dye to a reactive dye. 20 The latter holds promise as a reactive dye for the efficient coloration of (macro)molecules that present C=C double bonds.…”

“…DR1 3-mercaptopropionate (1) was synthesized, as reported previously. 19 Briefly, DR1 (1.04 g, 3.30 mmol), 4-dimethylaminopyridine (DMAP) (3 mg, 0.03 mmol), and 3-mercaptopropionic acid (1.49 mL, 16.50 mmol) were mixed in anhydrous DCM (100 mL) and stirred at 0 °C under a N 2 flow. Over a 10 min period, a solution of dicyclohexylcarbodiimide (DCC) (3.41 g, 16.50 mmol) in anhydrous DCM (30 mL) was added dropwise to the DR1 mixture and the reaction allowed to stir at 0 °C for 2 h. HCl (0.5 M, 300 mL) was then added, forming a white precipitate, which was removed by filtration.…”