Preparation of 2-substituted but-2-ene-1,4-dial-4-acetals and novel
hemiacetals of glyoxal monoacetals
    1.
    发明授权
    Preparation of 2-substituted but-2-ene-1,4-dial-4-acetals and novel hemiacetals of glyoxal monoacetals 失效
    2-取代的丁-2-烯-1,4-表面-4-缩醛的制备和乙二醛单缩醛的新半缩醛

    公开(公告)号:US5576449A

    公开(公告)日:1996-11-19

    申请号:US314955

    申请日:1994-09-29

    IPC分类号: C07D319/06

    CPC分类号: C07D319/06

    摘要: The preparation of 2-substituted but-2-ene-1,4-dial-4-acetals of the formula I ##STR1## in which the substituents R.sup.1 to R.sup.4 stand for hydrogen or C.sub.1 -C.sub.6 aliphatic radicals, and R.sup.2 and R.sup.3 or R.sup.1 and R.sup.2 are in each case common members of an aliphatic 4-membered to 7-membered ring, which can contain a hetero atom, and R.sup.5 denotes an alkyl, alkenyl, or alkynyl radical having from 1 to 12 C atoms, which can be substituted by cycloaliphatic, aromatic or heterocyclic radicals or by hydroxy, ether, thioether, acyl, alkylamino, carboxy, or carbalkoxy groups, an optionally substituted aryl radical or an alkoxy, alkylthio, or acyloxy group, whereina) glyoxal is caused to react with a 1,3-propanediol of the formula II ##STR2## in aqueous solution in the presence of an acid to form a monoacetal of the formula III ##STR3## is neutralized, and if necessary the components more readily volatile than the monoacetal III are distilled off,b) the monoacetal III obtained is caused to react with an aldehyde R.sup.5 CH.sub.2 --CHO in the presence of from 0.01 to 10 mol %, based on glyoxal, of a catalyst mixture of a secondary amine and an acid to form an aldol of the formula IV ##STR4## the components which are more volatile than the aldol IV being distilled off if necessary, andc) the aldol IV is dehydrated in the presence of a water-eliminating agent to form the product I,and novel hemiacetals of glyoxal monoacetals.

    摘要翻译: 制备其中取代基R 1至R 4代表氢或C 1 -C 6脂族基团的式I I 2的2-取代的丁-2-烯-1,4-二甲氧基-4-缩醛,以及R 2和R 3 或者R 1和R 2各自为可以含有杂原子的脂肪族4元〜7元环的共同成员,R 5表示具有1〜12个C原子的烷基,烯基或炔基,其可以 被脂环族,芳族或杂环基取代,或被羟基,醚,硫醚,酰基,烷基氨基,羧基或烷氧基取代,任选取代的芳基或烷氧基,烷硫基或酰氧基,其中a)使乙二醛反应 与式II II的1,3-丙二醇在酸存在下在水溶液中形成式III的单缩醛中和,如果需要,组分比单缩醛更容易挥发 III蒸馏掉,b)使获得的单缩醛III与醛反应 在基于乙二醛的0.01至10mol%的存在下,将仲胺和酸的催化剂混合物形成式IV的醛醇,得到更具挥发性的组分 如果需要,醛醇IV被蒸馏,和c)醛醇IV在除水剂存在下脱水以形成产物I,和乙二醛单缩醛的新型半缩醛。