posted on 2016-10-26, 00:00authored byJie Fu, Jing Mo, Qiurong Tian, Xiuyang Lu
1,2,4-Trifluorobenzene,
the decarboxylation product of 2,4,5-trifluorobenzoic
acid, is an important raw material for synthesizing sitagliptin phosphate,
the main medicinal treatment for diabetes. The traditional synthesis
suffers from environmental concerns; therefore, in this work, a series
of metal catalysts was employed to catalyze the decarboxylation of
2,4,5-trifluorbenzoic acid in NH3-enriched high-temperature
liquid water (HTLW) to address these concerns. Copper catalysts exhibited
excellent performance, and heterogeneous copper catalysts, such as
Cu and Cu2O, led to a higher yield of 1,2,4-trifluorobenzene
(89.1%) than homogeneous copper catalysts, such as CuCl2 and CuCl. The effects of catalyst loading and reactant loading on
the decarboxylation of 2,4,5-trifluorbenzoic acid were also investigated.
Increases in the catalyst and reactant loadings were favorable for
the decarboxylation of 2,4,5-trifluorbenzoic acid; however, a high
catalyst loading was not favorable. A reusability test with Cu2O revealed that Cu2O has excellent activity maintenance
in NH3-enriched HTLW.