Direct and Divergent Solid-Phase Synthesis of Azobenzene and Spiropyran Derivatives

Abstract

Here, we report a solid-phase approach to synthesize azobenzene and spiropyran derivatives. The divergent synthesis process requires no purification steps to obtain the desired product with a 28−55% yield, depending on the specific compound. For the spiropyran compounds, solid-phase resin cleavage is performed under mild conditions to minimize spiropyran ring opening. The solid-phase method enables the synthesis of a library of azobenzene and spiropyran derivatives without the need to develop purification strategies for each derivative.

Erianin-Loaded Photo-Responsive Dendrimer Mesoporous Silica Nanoparticles: Exploration of a Psoriasis Treatment Method

“…When irradiated with ultraviolet light with a wavelength of 365 nm, the spiropyran molecule changes from a hydrophobic state into a hydrophilic state, which causes the wetting of the nanoparticles. Then, the drug is released from the pores [ 32 ]. The chemical structures of spiropyran and erianin are shown in Figure 1 b,c.…”

“…The active hydrogen of the carboxyl group was rapidly exchanged with the active hydrogen in the solution, so it was not visible ( Figure 5 a). The a and b peaks of 13 C-NMR spectroscopy were assigned to the ester carbonyl carbon, indicating that DMSN@FSP was successfully synthesized [ 32 ] ( Figure 5 b). The Fourier-transform infrared (FTIR) technique was used to investigate the molecular bond signatures of DMSN and DMSN@FSP ( Figure 6 a).…”

Solvent Polarity Effects on the Mechanochemistry of Spiropyran Ring Opening

“…10−12 Reported mechanochromic probes include spiropyran (SP), 13,14 dioxetanes, 15 and rhodamine, 16,17 among others. SP force probes have received considerable attention owing to their accessible synthesis, 18 the high extinction coefficient of the merocyanine (MC) product of their mechanically coupled ringopening reaction (Figure 1), and the ability to tune their mechanochemical activity though regiochemistry or substituents. 13,14,19 SP probes have been explored in a range of polymer matrices, including polyacrylates, 13 polycaprolactone, 12,20 ate, 21 poly(ionic liquid), 22 acrylic latex, 23 polystyrene, 24 polyurethanes, 25 polyphenylenes, 26 and hydrogels.…”

Microwave-assisted rapid and sustainable synthesis of unsymmetrical azo dyes by coupling of nitroarenes with aniline derivatives

“…This method requires the use of toxic DMF as the solvent, high temperature, long reaction time, tedious work-up, and purification, and thus not suitable for batch processes ( Zhao et al., 2011 ). In recent times, the stringent environmental concerns have instigated the development of various alternative and greener strategies for the synthesis of azo dyes that include diazo coupling on clay, polymer, or resin-supported diazonium salts ( Caldarelli et al., 2000 ; Merrington et al., 2002 ; Dabbagh et al., 2008 ; Kollarigowda and Braun, 2021 ), and use of grindstone chemistry ( Eissa and Mohamed, 2018 ). Besides, a few continuous flow methods are also developed for diazo coupling ( Wang et al., 2019 ; Shukla et al., 2021 ).…”