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A suspension of 5.4 g (0.10 mol) of sodium methoxide in 50 mL of tetrahydrofuran (THF) was stirred at -20° to -10° while 17.7 g (0.10 mol) of 2-chloroethyl trifluoroacetate were added dropwise. The resulting clear solution was allowed to warm with precipitation commencing at about 10° and a slow exotherm ensuing to 35°. The mixture was maintain below 35° until the exotherm subsided and then was stirred for 4 h. Filtration and fractionation of the filtrate gave 7.4 g (43% yield) of 2-methoxy-2-trifluoromethyl-1,3-dioxolane, b.p. 61°-62° at 3.3 kPa (25 mm). IR (neat): 3000, 2965, 2925, and 2680 (sat'd CH), 1250-1100 cm-1 (CF, C--O). NMR (CCl4): 1H 4.17 (m, 4H, ring CH2 and 3.33 ppm (s, 3H, OCH3); 19 F-85.0 ppm (s, CF3).

1. additionwere added dropwise
2. temperatureto warm with precipitation commencing at about 10°
3. customensuing to 35°
4. temperatureThe mixture was maintain below 35° until the exotherm
5. filtrationFiltration and fractionation of the filtrate