been charged with 38 0 g of potassium carbonate to the dark suspension was added within 60 min at 86 90 u00b0 c a solution of 70 4 g 250 mmol of 2 5 methyl 2 phenyl 4 oxazolyl ethanol methanesulfonyl ester in 275 ml of dmf the reaction mixture was stirred at the same temperature for 6 h then 450 ml of toluene followed by 950 ml of water were added whereas the temperature was kept above 75 u00b0 c the aqueous phase was separated and extracted with 150 ml of warm toluene the two toluene phases were combined re extracted with water and finally treated at a temperature between 65 and 40 u00b0 c with 900 ml of methanol the resulting suspension was stirred for 1 h at 40 u00b0 c cooled to u2212 15 u00b0 c and stirred for 3 h at u2212 15 u00b0 c finally the suspension was filtered the filter cake was washed with 100 ml of a cold u2212 15 u00b0 c toluene methanol mixture and dried at 60 u00b0 c 10 mbar to afford 76 8 g 84 5 of 4 2 5 methyl 2 phenyl 4 oxazolyl ethoxyl benzo b thiophene 7 carbaldehyde as colorless crystals with a m p of 154 u00b0 c a 4 l 4 necked glass reactor equipped with a mechanical stirrer a thermometer a cooler a dropping funnel a water separator and an argon inlet was charged under argon in sequence with 115 0 g 300 mmol of 4 2 5 methyl 2 phenyl oxazol 4 yl ethoxy benzo b.