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    • 50. 发明授权
    • Purification of esters of tetrahydro-pyran-4-carboxylic acid
    • 四氢 - 吡喃-4-羧酸酯的纯化
    • US5414097A
    • 1995-05-09
    • US185179
    • 1994-01-24
    • Rolf FischerNorbert GoetzThomas KuekenhoehnerHarald RustWerner Schnurr
    • Rolf FischerNorbert GoetzThomas KuekenhoehnerHarald RustWerner Schnurr
    • C07D309/08
    • C07D309/08
    • A process for purifying esters of tetrahydropyran-4-carboxylic acid of the formula I ##STR1## where R.sup.1 to R.sup.3 are each C.sub.1 -C.sub.4 -alkyl, and R.sup.2 and R.sup.3 are each additionally hydrogen, from mixtures produced in the reaction of butyrolactones of the formula II ##STR2## where R.sup.2 and R.sup.3 have the abovementioned meanings, and R.sup.4 is hydrogen, alkyl of 1-6 carbons or acyl of the formula --CO--R.sup.2, with alcohols of the formula R.sup.1 OH in the presence of oxide catalysts, by distillation, which entailsa) removing overhead, in a first column with 5-25 theoretical plates with a distillate pressure of 700-1100 mbar and a distillate temperature of 50.degree.-80.degree. C., an alcohol and up to 10% of the water,b) transferring the bottom product from the first column into a second column with 18-40 theoretical plates, into which a water entrainer is metered between plates 15 and 30, and is circulated, and which operates with a distillate pressure of 35-350 mbar and a distillate temperature of 18.degree.-70.degree. C., with the esters of tetrahydropyran-4-carboxylic acid being removed between plates 8 and 18 at 90.degree.-150.degree. C., and, where appropriate,c) feeding the bottom product from the second column into a third column with 5-25 theoretical plates, and returning the overhead products at a distillate pressure of 1-100 mbar and a distillate temperature of 90.degree.-140.degree. C. to the synthesis of the esters of tetrahydropyran-4-carboxylic acid.
    • 用于纯化式I的四氢吡喃-4-羧酸的酯的方法,其中R 1至R 3各自为C 1 -C 4 - 烷基,R 2和R 3各自为氢, 其中R 2和R 3具有上述含义,R 4是氢,1-6个碳的烷基或式-CO-R 2的酰基,其中式R 1 OH的醇在存在下 氧化物催化剂,通过蒸馏,其需要a)在具有5-25理论塔板的第一塔中,馏出物压力为700-1100毫巴,馏出物温度为50-80℃,醇和升高 至10%的水,b)将底部产物从第一塔转移到具有18-40理论塔板的第二塔中,其中在15和30之间计量水夹带剂,并循环,并且其以 馏出液压力为35-350毫巴,馏出物温度为18-70℃, 其中四氢吡喃-4-羧酸的酯在90℃-150℃下在板8和18之间除去,并且在适当的情况下,c)将底部产物从第二塔进料到具有5-25理论值的第三塔 将塔顶馏出物返回到馏出物压力为1-100毫巴,馏出液温度为90-140℃,以合成四氢吡喃-4-羧酸酯。