申请人:Roche Vitamins Inc.
公开号:US05990360A1
公开(公告)日:1999-11-23
A novel process for the manufacture of a .gamma.-halotiglic aldehyde HalH.sub.2 C-CH.dbd.C(CH.sub.3)-CHO [I], wherein Hal signifies chlorine or bromine, comprises haloalkoxylating a 1-alkoxy-2-methyl-1,3-butadiene H.sub.2 C.dbd.CH-C (CH.sub.3).dbd.CH-OR.sup.1 [II], wherein R.sup.1 signifies C.sub.1-4 -alkyl, using a particular halogenating agent in a C.sub.1-4 -alkanol (R.sup.2 OH) and hydrolyzing the thus-obtained .gamma.-halotiglic aldehyde dialkyl acetal HalH.sub.2 C-CH.dbd.C(CH.sub.3)-CH (OR.sup.1)(OR.sup.2) [III] to the desired .gamma.-chloro- or .gamma.-bromotiglic aldehyde I. The halogenating agent used in this process is selected from an alkali metal hypochlorite, an alkali metal hypobromite, an alkaline earth metal hypochlorite, an alkaline earth metal hypobromite, tert.butyl hypochlorite, N-bromoacetamide, 1.3-dichloro-5,5-dimethylhydantoin and 1,3-dibromo-5,5-dimethylhydantoin. Further aspects of the present invention are the use of the thus manufactured .gamma.-halotiglic aldehyde for the production of .gamma.-acetoxy-tiglic aldehyde or of a Wittig aldehyde halide Hal-Ph.sub.3 P.sup.+ CH.sub.2 -CH.dbd.C(CH.sub.3)-CHO [VII], wherein Hal signifies chlorine or bromine and Ph a process for the catalytic dealkoxylation of the 1,1,3-trialkoxy-2-methyl-butane CH.sub.3 -CH(ORl)-CH(CH.sub.3)-CH(OR.sup.1).sub.2 [VI] to the corresponding 1-alkoxy-2-methyl-1,3-butadiene II in the gas phase using an aluminium silicate of medium specific surface as the catalyst. The products I, .gamma.-acetoxy-tiglic aldehyde and VII are known, important intermediates for the production of various apocarotenoids and diapocarotenoids as well as of Vitamin A.
一种制造.gamma.-卤代腈醛HalH.sub.2C-CH.dbd.C(CH.sub.3)-CHO [I]的新工艺,其中Hal表示氯或溴,包括使用特定的卤代试剂在C.sub.1-4-烷醇(R.sup.2OH)中进行1-烷氧基-2-甲基-1,3-丁二烯H.sub.2C.dbd.CH-C(CH.sub.3).dbd.CH-OR.sup.1 [II]的卤代烷氧化反应,并将所得的.gamma.-卤代腈醛二烷基缩醛HalH.sub.2C-CH.dbd.C(CH.sub.3)-CH(OR.sup.1)(OR.sup.2) [III]水解为所需的.gamma.-氯代或.gamma.-溴代腈醛I。在该工艺中使用的卤代试剂选自碱金属次氯酸盐、碱金属次溴酸盐、碱土金属次氯酸盐、碱土金属次溴酸盐、叔丁基次氯酸盐、N-溴代乙酰胺、1,3-二氯-5,5-二甲基异噻唑啉和1,3-二溴-5,5-二甲基异噻唑啉。本发明的进一步方面是使用所制造的.gamma.-卤代腈醛生产.gamma.-乙酰氧基-腈醛或Wittig腈醛卤化物Hal-Ph.sub.3P.sup.+ CH.sub.2-CH.dbd.C(CH.sub.3)-CHO [VII],其中Hal表示氯或溴,Ph是苯基,以及一种在气相中使用中等比表面积的硅铝酸盐作为催化剂对1,1,3-三烷氧基-2-甲基丁烷CH.sub.3-CH(ORl)-CH(CH.sub.3)-CH(OR.sup.1).sub.2 [VI]进行催化脱烷氧基反应制备相应的1-烷氧基-2-甲基-1,3-丁二烯II。产品I、.gamma.-乙酰氧基-腈醛和VII是生产各种类胡萝卜素和二级类胡萝卜素以及维生素A的重要中间体。