Patent ID: 7858811

Claim:
A process for the preparation of a compound of formula I wherein both R 7 are, independently, C 1 -C 6 alkyl, or together are —CH 2 —CH 2 —CH 2 —; wherein (a) a compound of formula III wherein Hal is halogen; is reacted with a compound of formula IV wherein both R 7 are, independently, C 1 -C 6 alkyl, or together are —CH 2 —CH 2 —CH 2 —; in the presence of an acid, or a mixture of an acid and an organic solvent, and tetraphenyl phosphonium chloride; (b) followed by optional addition of extra solvent, and by neutralization with a base, and (c) cyclization in the presence of a palladium catalyst and a base.