A SPIRO-INDOLE DERIVATIVE, C16H10CLFN2O2S

The spiro-indole derivative, 5-chloro-3'-(4-fluoro-phenyl)spiro[3H-indole-3,2'-thiazolidine]-2,4'(1H)-dione, has been synthesized by the reaction of mercaptoacetic acid with 5-chloroimino-3-(4-fluoro-phenyl)-2H-indol-2-one. The latter compound is prepared in situ from 5-chloroindole-2,3-dione and 4-fluoroaniline. The structure of the title compound confirms the conclusions drawn from the spectroscopic studies that the environment of the spiro C atom is based on tetrahedral geometry having bond angles in the range 109.6 (3)-117.3 (2)-degrees.