Further Substitution on the A Ring In those instances where R3, R4 or R5 is a halogen, preferably iodo or bromo, the A ring can be further substituted by carrying out a Heck reaction, or as shown in Reaction Scheme VII. As shown above, the compound of Formula I in which R4 is iodo is reacted with dimethylacrylamide in an inert solvent, for example N,N-dimethylformamide, in the presence of a quarte