Synthesis of Fluorenes and Their Related Compounds from Biaryls and Meldrum’s Acid Derivatives

A new synthetic method for preparing fluorenes from amino group-containing biaryls and Meldrum’s acid derivatives was developed. The reaction proceeded without a catalyst and loss of functional groups. The corresponding...

Innovative Bio-Based Organic UV-A and Blue Light Filters from Meldrum’s Acid

Faced with the ban of some organic UV filters such as octinoxate or avobenzone, especially in Hawaii, it became essential to offer new alternatives that are both renewable and safe for humans and the environment. In this context, a class of bio-based molecules displaying interesting UV filter properties and great (photo)stability has been developed from Meldrum’s acid and bio-based and synthetic p-hydroxycinnamic acids, furans and pyrroles. Moreover, p-hydroxycinnamic acid-based Meldrum’s derivatives possess valuable secondary activities sought by the cosmetic industry such as antioxidant and anti-tyrosinase properties. The evaluation of the properties of mixture of judiciously chosen Meldrum’s acid derivatives highlighted the possibility to modulate secondary activity while maintaining excellent UV protection. Meldrum’s acid derivatives are not only competitive when benchmarked against organic filters currently on the market (i.e., avobenzone), but they also do not exhibit any endocrine disruption activity.

Uncatalyzed Synthesis of New Antibacterial Bisarylidene Meldrum's Acid Derivatives Functionalized with Ether Groups

A series of new bisarylidene Meldrum’s acid derivatives (3a-i) were prepared in high yield by a condensation reaction between Meldrum's acid and ether functionalized dibenzaldehyde, without any catalyst. Regardless of the nature of the substitution, all the reactions were completed within 2-3 hours in ethanol at reflux condition. In the reactions, the column purification of the products was not needed. The FT-IR, 1H-NMR, 13C-NMR and mass spectra confirm the structure of the products. Furthermore, the antibacterial activities of some synthesized compounds were investigated. According to the results, these compounds showed good activities against Staphylococcus aureus, Bacillus cereus, E. coli and Pseudomonas aeruginosa.