| 摘要 |
Prodn. of malonate esters of formula (I) R"R"'C(COOR')2 (where R' is opt. unsatd. and/or opt. branched 1-18C aliphatic hydrocarbyl or substd. alkyl. R" and R"' are H or is not >18C hydrocarbyl) comprises first reacting an R-substd. phenylsulphonylisocyanate (II) (where R is H, alkyl, halo, alkoxy or NO2) with a ketene O is C is CR"R"' (III) in a nitroalkane or alkyl halide at 0-80 degrees C.The resulting azetidinedione is reacted with R'OH at normal or autogenous pressure at 100-160 degrees C to give (I) and the arylsulphonamide. This is reacted with COCl2 to give (II) for recycle.(I) is obtd. in high yields and purity >=99%. The sulphonamide is obtd. in very pure form for conversion to (II).
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