US 10,725,377 B2  12  11  -continued  -continued  I~  o- #  o- usDusD  I~  o- #  o- usD usD  o~o’-....  ¢0  ¢0  usDusD  Q  Ok  O=S=O  ¢0  ¢0  SD  SD  ~  ~  ~  ~  U  1,,,,() ¢  I  o- #  o- SD  SD  ~  ~  ~  ~  I  I  #  ~  #  I~  #  o- psD  ~  ~  I  I  -""o  -"" 0  F  The sulfonium compound having formula (A) may  be  synthesized by a combination of well-known organic  chem- istry methods, for example, according to the scheme  shown  below. 