New family of dyes

Description of the technology

The Institute of Organic Synthesis at the University of Alicante has developed an innovative method for synthesizing a new family of indolizines with dye properties. A prominent feature of this method is that the molecules of interest are obtained in one step from commercially available materials under mild reaction conditions (room temperature and atmospheric pressure). The compounds obtained are solvatochromic, that is, their colors vary according to the solvent used. The technology is environmentally friendly and the method is rapid and selective with yields higher than 70%. These novel compounds can be customized for any industry application with potential interest. The group is looking for companies interested in acquiring this technology for commercial exploitation through licensing agreements of the patent, manufacturing agreements or research agreements to develop new applications.

Specifications

In order to overcome limitations described above, it has been explored synthesis of novel indolizine dyes and succeeded in developing a novel efficient synthetic route. This invention relates to a new family of indolizines with dye properties and its production involves the use of a single starting material. This is an indolizine which is transformed into another more substituted indolizine with dye properties, under mild reaction conditions (room temperature and atmospheric pressure) The main innovation of this method of synthesis is that the new substituent that binds to the indolizine nucleus is derived from another molecule of the starting indolizine (A + A → T), and it is selectively incorporated into a specific position in the molecule. Therefore, the present invention relates to a new indolizine with solvatochromic properties and a novel, selective and effective synthetic procedure of these dyes from simpler indolizines. Alternatively, the indolizine dyes can be obtained through multicomponent synthesis (from commercially available materials) of the precursor indolizine of the dye in a single reaction vessel. In this case, the isolation and purification of the dye precursor indolizine is unnecessary, showing a similar yield but with a decrease in the cost and time of production. The synthetic process is very simple (it is produced in a single reaction vessel) and the dyes obtained are orange-red solids (Figure 1). In addition, this new class of compounds has the interesting and advantageous property of being solvatochromic, that is, its color depends on the solvent used, with the potential applications that can appear. This feature is due to the chromophore group which is selectively inserted at the 7-position of the starting indolizine (which comes from another indolizine homologous), providing a high conjugation and, therefore, solvatochromic dye properties. Thus, a different dye color can be obtained according to the solvent used for dissolving the solid indolizine (hexane, dichloromethane, chloroform, 1,4-dioxane, ethanol, acetonitrile and N,N-dimethylformamide) (Figure 2).

Main advantages of its use

• The selectivity of the reaction is very high. The indolizine dye is obtained with absolute control, obtaining a single isomer of the ten possible.
• It does not require the use of inert atmosphere, dry solvents or physical activation (heat or radiation) to obtain the final product.
• It is an environmentally friendly technology. It does not use solvents such as dioxane, pyridine, chloroform or benzene.
• It produces indolizine dyes in yields higher than 70%.
• It reduces costs, increases the final yield and less waste is generated.
• This process is carried out at room temperature and atmospheric pressure, which simplifies the method and decreases production costs.

Applications

• Alternative energy (solar energy and photovoltaic solar).
• Chemicals and materials (plastic industry, homogeneous injections/extrusions, non-homogeneous injections/extrusions, polymer (plastics) materials).
• Cosmetics.
• Electrochromic devices.
• Electronic chemicals.
• Leather tanning.
• Optical filters.
• Paints.
• Photoelectric converters (solar cells)
• Photothermography.
• Recording devices and laser scanning.
• Scanning related.
• Staining and dyeing materials.
• Textile (synthetic and natural).
• Thermography.

Additional information (attached documents)

• Dye in the solid state and in solution - Fig1.jpg
• Solvatochromic effect - Fig2.jpg
• Pilot plant - Pilot plant.jpg
• Pilot plant (GMPs) - Pilot plant.jpg