Potassium Carbonate → HCID 13117186, 화합물

21 g (0.06 mole) of 2-[4-(6-chloro-2-benzthiazolyloxy)-phenoxy]-propionic acid were initially taken together with 10.4 g (0.075 mole) of potassium carbonate in 100 ml of acetone and the mixture was stirred for approx. 1/2 hour at 45° C., a thick paste being formed. 11.6 g (0.07 mole) of 2-bromobutyrolactone in 50 ml of acetone were then added dropwise in the course of 1/2 hour. When the addition was complete, the reaction mixture became highly fluid; the conversion was followed by means of thin-layer chromatography and was approx. 70% after 5 hours. Altogether, the mixture was stirred for 16 hours at approx. 50° C. After cooling, the salt was filtered off, the acetone was removed by distillation and the residue was taken up in approx. 200 ml of toluene and washed with water and saturated sodium bicarbonate solution. After drying, the toluene was removed by distillation and the residue remaining was dried in vacuo (0.05 mbar) for one hour at approx. 70° C. The product remaining after drying was 22 g (91.3% of theory) of a very viscous oil, which was identified by 1H nuclear magnetic resonance spectroscopy as 2-oxotetrahydrofuran-3-yl 2-[4-(6-benzthiazolyloxy)-phenoxy]-propanoate. ##STR12##