abstract |
PCT No. PCT/US97/13723 Sec. 371 Date Oct. 23, 1998 Sec. 102(e) Date Oct. 23, 1998 PCT Filed Jul. 16, 1997 PCT Pub. No. WO98/04937 PCT Pub. Date Feb. 5, 1998The invention relates to photochromic compounds of general formula (I), in which: R3 and R5 are C1-C6 alkoxy groups and the rest of the R groups represent various substituents. |