US 10,754,248 B2  133  134  $^{19}$F-NMR (500 MHz, in DMSO-d$_{6}$ ): o=-76.1 (6F, m),  - 74.5 (6F, m) ppm  sulfonium salt having a cation represented by the general  formula (1’), not the sulfonium salt of the present invention.  <PAG-10>  $^{1 }$H-NMR (500 MHz, in DMSO-d$_{6}$ ): o=l.64 (6H, m), 1.83  (6H, d), 1.95 (3H, s), 3.54 (2H, s), 4.55 (2H, s), 7.41 (2H,  m), 7.74-7.79 (SH, m), 7.81-7.86 (4H, m), 8.56 (lH, s) ppm  [Synthesis Example 1-10] Synthesis of PAG-10 for  Comparison  Time-of-flight mass spectrometry (TOFMS; MALDI)  POSITIVE M+459 (equivalent to C$_{22}$H$_{17}$F$_{6}$ 0 $_{2}$S+)  NEGATIVE M-211 (equivalent to C$_{4}$HF$_{6}$ 0 3 -)  A mixed solution of a photo acid generator (PAG-3) (7.8 40  g), a sulfonate salt (6-1) (8.6 g), methylisobutylketone (50  g), and pure water (30 g) was stirred for 10 minutes to  dispense an organic layer. The obtained organic layer was  cleaned with pure water ( 40 g) 4 times, and concentrated  under reduced pressure to remove a solvent by evaporation.  45  By silica gel column chromatography and purification, a  target photo acid generator (PAG-10) (9.5 g) was synthe› sized as an amorphous solid (yield: 87%). The PAG-10 is a  Time-of-flight mass spectrometry (TOFMS; MALDI)  POSITIVE M+459 (equivalent to C$_{22}$H$_{17}$F$_{6}$ 0 $_{2}$S+)  NEGATIVE M-423 (equivalent to C$_{15}$H$_{17}$F$_{6}$ 0 $_{5}$S-)  [Synthesis Example 1-11] Synthesis of PAG-11 for  Comparison  (PAG-3)  $^{19}$F-NMR (500 MHz, in DMSO-d$_{6}$ ): o=-76.1 (6F, s),  -72.3 (6F, s) ppm  (PAG-3)  Q }QyO~SOi  USUO~OH CC;  F3C  CF3  (PAG-10) 