Synthesis of Stenhouse salts from 4-((furan-2-yl)methylene)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one

In recent years, Stenhouse salts (SSs) have attracted much attention as intermediates for the synthesis of cyclopenten‐2‐enones. These compounds were formed from the ring opening of furan derivatives by amines. This reaction uses in the identification of furfural in food products due to the intense color of these salts as a result of its conjugated triene structure.1 Donor acceptor Stenhouse adducts (DASAs) are a new class of negative photoswitches. These compounds easily synthesized in two steps from commercially available starting materials.2 DASAs were applied in smart materials, sensors, catalysis and also used as drug-carriers.3 Furfural is a chemical product that can be derived from plant waste. It used as a readily available starting material to synthesize a wide range of materials.4 Herein we design and synthesis of a new class of photochromes based on furfural, termed donor-acceptor Stenhouse adducts. We described DASAs containing alkyl-based amine “donors” (electron-rich) and pyrazolone “acceptors” (electron-deficient).

Keywords:

Stenhouse salts , Pyrazolone , Furfural , Donor acceptor Stenhouse adducts