摘要:
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 signifies phenyl, as well as a process for the catalytic dealkoxylation of the 1,1,3-trialkoxy-2-methyl-butane CH.sub.3 --CH(OR.sup.1)--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.
摘要:
A process for the manufacture of a .gamma.-acetoxy-tiglic aldehyde by reacting a .gamma.-bromotiglic aldehyde or a .gamma.-chlorotiglic aldehyde with sodium acetate or potassium acetate in an organic solvent in the presence of a phase transfer catalyst.
摘要:
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.
摘要:
A process for the manufacture of 5-cyano-4-methyl-oxazole which comprises reacting a 5-(lower alkoxycarbonyl)-4-methyl-oxazole with ammonia in the gaseous phase, in the presence of a zirconium oxide or hafnium oxide catalyst.
摘要:
The present invention provides a method of making alkali metal and alkaline earth metal salts of L-ascorbic acid 2-monophosphate comprising reacting a L-ascorbic acid 2-polyphosphate under alkaline conditions with an alkali metal or alkaline earth metal salt of L-ascorbic-acid in concentrated aqueous solution. The amount of the L-ascorbic acid salt is in molar excess of the polyphosphate and the pH value of the reaction medium is maintained in the range of from about 8 to about 11 wherein the reaction is carried out until substantially all of the polyphosphate has been consumed and only L-ascorbic acid 2-monophosphate salt is present. A further aspect of the present invention comprises spray drying the mixture obtained after completion of the reaction, cooling and dilution to a suitable viscosity. The product of the process according to the invention is suitable as an additive for human and animal foodstuffs; it is especially stable against oxidative and thermal degradation and has an especially high content of L-ascorbic acid monophosphate vis-a-vis polyphosphates and is accordingly primarily of use preferably for the nutritional enrichment of fish feed.
摘要翻译:本发明提供一种制备L-抗坏血酸2-单磷酸的碱金属和碱土金属盐的方法,其包括在碱性条件下使L-抗坏血酸2-多磷酸酯与L-抗坏血酸的碱金属或碱土金属盐反应, 酸在浓缩水溶液中。 L-抗坏血酸盐的量与多磷酸盐摩尔过量,反应介质的pH值保持在约8至约11的范围内,其中进行反应直到基本上所有的多磷酸盐已经被 并且仅存在L-抗坏血酸2-单磷酸盐。 本发明的另一方面包括将反应完成后获得的混合物喷雾干燥,冷却和稀释至合适的粘度。 本发明方法的产品适用于人和动物食品的添加剂; 它对氧化和热降解特别稳定,并且具有特别高含量的L-抗坏血酸单磷酸酯vis-+ E,gra a + EE -vis多磷酸盐,因此主要用于鱼饲料的营养富集。
摘要:
The invention is concerned with a process for the manufacture of 5-cyano-4-lower alkyl-oxazoles by dehydrating a 5-carbamoyl-4-lower alkyl-oxazole in the gas phase in the presence of a heterogeneous catalyst based on silicon dioxide and in the presence of an inert solvent. The heterogeneous catalyst used is formed SiO.sub.2 or SiO.sub.2 doped with an oxide of V, Mo, Fe, Co and/or Zn. An N-lower alkyl-pyrrolidone is preferably used as the inert solvent.
摘要:
The invention is concerned with a process for the manufacture of beta-isophorone from alpha-isophorone by converting alpha-isophorone into beta-isophorone in the presence of a heterogeneous catalyst in the gas phase. The heterogenous catalyst used is especially an oxide or mixed oxide of the elements Mg, Al, Si and Ni.
摘要:
A process for the manufacture of ketopantolactone of the formula ##STR1## from pantolactone, which comprises dehydrogenating pantolactone in the presence of a vanadium oxide-containing or molybdenum oxide-containing catalyst with oxygen or an oxygen-containing gas in the gas phase.