申请人:BASF Aktiengesellschaft
公开号:US04845269A1
公开(公告)日:1989-07-04
3-pentenoates are prepared from 2-pentenoates by a process in which (a) a 2-pentenoate of the formula ##STR1## where R.sup.1 is alkyl of 1 to 12 carbon atoms, cycloalkyl of 5 to 8 carbon atoms, aralkyl of 7 to 10 carbon atoms or aryl of 6 to 10 carbon atoms, is reacted with a compound of the formula II R.sup.2 -X-H II where R.sup.2 has the meanings given for R.sup.1 and X is an oxygen or sulfur atom, or with a compound of the formula III ##STR2## where R.sup.3 is hydrogen or R.sup.3 and R.sup.4 are each alkyl of 1 to 12 carbon atoms, cycloakkyl of 5 to 8 carbon atoms, aralkyl of 7 to 10 carbon atoms or aryl of 6 to 10 carbon atoms, and R.sup.3 and R.sup.4 together with the nitrogen atom on which they are substituents may form a 5-membered to 7-membered ring which may additionally contain a nitrogen or oxygen atom as a hetero atom, at from 20.degree. to 300.degree. C., in the presence or absence of a basic catalyst, to give a compound of the formula IV ##STR3## where Y is --XR.sup.2 or ##STR4## in which X, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 have the above meanings, and (b) the compound of the formula IV is cleaved in the liquid or gas phase in the presence of an acidic catalyst at from 150.degree. to 450.degree. C. to give a mixture of 3- and 2-pentenoates, and the 3-pentenoate is isolated.
3-戊烯酸酯是通过以下过程从2-戊烯酸酯制备的:(a)反应式为##STR1##其中R.sup.1是1至12个碳原子的烷基、5至8个碳原子的环烷基、7至10个碳原子的芳基烷基或6至10个碳原子的芳基的2-戊烯酸酯与化合物II R.sup.2 -X-H II反应,其中R.sup.2具有R.sup.1所给出的含义,X是氧或硫原子,或与化合物III的式子反应##STR2##其中R.sup.3是氢或R.sup.3和R.sup.4均为1至12个碳原子的烷基、5至8个碳原子的环烷基、7至10个碳原子的芳基烷基或6至10个碳原子的芳基,且R.sup.3和R.sup.4与它们所取代的氮原子可以形成5-至7-成员环,该环还可以含有一个氮或氧原子作为杂原子,在20℃至300℃下,在存在或缺乏碱性催化剂的情况下,得到式子IV的化合物##STR3##其中Y是--XR.sup.2或##STR4##其中X、R.sup.1、R.sup.2、R.sup.3和R.sup.4具有上述含义,(b)在存在酸性催化剂的液相或气相中,将式子IV的化合物在150℃至450℃下裂解,得到3-戊烯酸酯和2-戊烯酸酯的混合物,并分离出3-戊烯酸酯。