abstract |
The present invention relates to formulas (3) and (1) wherein n is 0 or 1, R 11 and R 12 are the same, and CN, OR 300 , Si (R 301 ) 3 , NHR 302 , NR 303, R 304 , SR 305 and R 306 , or R 11 and R 12 together are selected from the group consisting of (a), (b) and (c) And X is Cl, Br or I] and provides a process for the preparation of compounds of formula (3), including compounds of formula (1) as basic intermediates. |