反应详情

To a solution of 4-biphenylthiol (2.79 g., 0.015 mole) in dry tetrahydrofuran (30 ml) and dimethylformamide (6 ml) was added portionwise sodium hydride (0.37 g., 0.015 mole) with stirring under a nitrogen atmosphere. The resulting solution was added dropwise over 45 min. to ethyl bromopyruvate (3.0 g, 0.015 mole) in dry tetrahydrofuran (30 ml) with stirring under nitrogen at -7° to -10° C. After 1 hr. at 25° C. ice-water (250 ml) was added. Extraction with methylene chloride (3×50 ml) followed by evaporation of the extract, and recrystallization of the residue from carbon tetrachloride gave 1.56 g (35%) of ethyl 3-(4-biphenylylthio)-2-oxopropionate, m.p. 154.5°-156° C.

1. stirringwith stirring under nitrogen at -7° to -10° C
2. extractionExtraction with methylene chloride (3×50 ml)
3. customfollowed by evaporation of the extract, and recrystallization of the residue from carbon tetrachloride