In 2019,Polymer Chemistry included an article by Pan, Haiyan; Chen, Siqi; Jin, Ming; Malval, Jean-Pierre; Wan, Decheng; Morlet-Savary, Fabrice. Application In Synthesis of Methyl 2-chloro-2-oxoacetate. The article was titled 《A substituent para-to-ortho positioning effect drives the photoreactivity of a dibenzothiophene-based oxalate series used as LED-excitable free radical photoinitiators》. The information in the text is summarized as follows:
Four dibenzothiophene (DBT)-based Me oxalates, synthesized through a one-step Friedel-Crafts acylation reaction, were developed as high-performance photoinitiators (PIs) for the free radical polymerization of acrylate resins excitable using LED sources that emit in the near-UV and visible region (i.e. 365-425 nm). These type I PIs show good optical absorption properties (ε365nm = 1 000-5300 M-1 cm-1). Their resp. photophys. properties, as well as the sequential photocleavage mechanism, were investigated using a large set of theor. and exptl. methods. A relevant structure/reactivity relationship opening the way to enhancing the PI performance is highlighted. Indeed, a para-to-ortho positioning effect of the oxalate-based substituent regulates both the absorption and photocleavage abilities within this DBT series. Para-isomers consequently exhibit a photoinitiating reactivity, whose efficiency is more than one order of magnitude higher than that of their ortho homologues. Associated with a H-donor alkylamine co-reactant, these photoinitiating efficiencies can be amplified even more due to an addnl. reaction pathway that judiciously assigns a new role to the aryloyl radical byproducts. These results correlate the PI photopolymerization performance with the photoinduced processes occurring in the excited states. The experimental process involved the reaction of Methyl 2-chloro-2-oxoacetate(cas: 5781-53-3Application In Synthesis of Methyl 2-chloro-2-oxoacetate)
Methyl 2-chloro-2-oxoacetate(cas: 5781-53-3) belongs to acyl chlorides. In the laboratory, acyl chlorides are generally prepared by treating carboxylic acids with thionyl chloride (SOCl2). The reaction is catalyzed by dimethylformamide and other additives.Application In Synthesis of Methyl 2-chloro-2-oxoacetate
Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics