申请人:Kuraray Co., Ltd.
公开号:US04224252A1
公开(公告)日:1980-09-23
Disclosed are improved procedures for preparing pinacolone from compounds of general formula (I) ##STR1## wherein, either adjacent two of A, B, C and D form a single bond between them and the remaining two are hydrogen atoms, or both A and D are hydrogen atoms and one of B and C is a hydrogen atom and the other represents OH, Cl, Br, HSO.sub.4, H.sub.2 PO.sub.4 or ClO.sub.4, and a new procedure which enables preparing pinacolone from a compound of general formula (II) ##STR2## wherein, both W and Y are each hydrogen atoms and X and Z are the same or different and each represents OH, Cl, Br, HSO.sub.4, H.sub.2 PO.sub.4, ClO.sub.4 or RCOO wherein R is a hydrogen atom or an alkyl group of 1 to 3 carbon atoms, or one of W and Y is a hydrogen atom and the other forms a single bond together with X, and Z represents OH, Cl, Br, HSO.sub.4 H.sub.2 PO.sub.4, ClO.sub.4 or RCOO where R is defined as above. In the process of preparing pinacolone from compounds of formula (I) by reacting them with formaldehyde in the presence of a strong inorganic acid, the process can be improved by adding a salt of a strong inorganic acid, or a compound of formula (II). Pinacolone can also be produced by heating a compound of general formula (II) in the presence of a strong inorganic acid and this reaction, too, can be improved by the addition of a salt of a strong inorganic acid. The use of a salt of a strong inorganic acid according to the invention makes it possible to reduce the concentration and the amount of strong acid normally required, and to improve the yield of pinacolone.
揭示了从一般式(I)的化合物制备异丁酮的改进程序,其中,A、B、C和D中的相邻两个形成它们之间的单键,其余两个是氢原子,或者A和D都是氢原子,B和C中的一个是氢原子,另一个代表OH、Cl、Br、HSO.sub.4、H.sub.2 PO.sub.4或ClO.sub.4,以及一种新的程序,可以从一般式(II)的化合物制备异丁酮,其中,W和Y都是氢原子,X和Z相同或不同,每个代表OH、Cl、Br、HSO.sub.4、H.sub.2 PO.sub.4、ClO.sub.4或RCOO,其中R是氢原子或1至3个碳原子的烷基,或者W和Y中的一个是氢原子,另一个与X形成单键,Z代表OH、Cl、Br、HSO.sub.4、H.sub.2 PO.sub.4、ClO.sub.4或RCOO,其中R如上所定义。通过在强无机酸存在下将一般式(I)的化合物与甲醛反应来制备异丁酮的过程可以通过添加强无机酸的盐或一种式(II)的化合物来改进。异丁酮也可以通过在强无机酸存在下加热一般式(II)的化合物来生产,这个反应也可以通过添加强无机酸的盐来改进。根据本发明使用强无机酸的盐可以降低通常所需的强酸浓度和量,并提高异丁酮的产率。