. "S (0) 2-, Rd is hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or Qa, Re is an alkyl group having 1 to 8 carbon atoms,-A6-Qa, - (CH2) iRl4,-OR28,-SR28, or-N (R29) (R30), i is an integer of 1 to 3, Ri4 is hydroxyl group, an alkoxy group having 1 to 4 carbon atoms, carboxyl group, or an N, N- dialkylcarbamoyl group having 1 to 4 carbon atoms, R28 is an alkyl group having 1 to 8 carbon ato" . . .