A solution of (5-difluoromethoxy-3-oxo-1,3-dihydro-isobenzofuran-1-yl)-triphenyl-phosphonium bromide (11.4 g, 21 mmoles), prepared as described in example 96, in dry CH2Cl2 (110 ml), under N2, was added with 3,5-dichloro-4-formyl-pyridine (4.06 g, 23.1 mmoles). The mixture was cooled to 4° C. and added with triethylamine (3.8 ml, 27.3 mmoles) while keeping the temperature below 10° C. At the end of the addition the mixture was stirred at room temperature for 3 hours, then cooled and added with 5% HCl. The organic phase was washed with an aqueous NaCl solution, discoloured with charcoal, filtered over celite and dried to give 14.4 g of the title compound (stoichiometric yield; containing 1 equivalent of triphenylphosphine oxide).
