公开(公告)号：US5189215A

公开(公告)日：1993-02-23

申请号：US784746

申请日：1991-10-28

申请人： Lorenz Farnleitner ,  Hubert Stuckler ,  Herbert Kaiser ,  Engelbert Kloimstein

发明人： Lorenz Farnleitner ,  Hubert Stuckler ,  Herbert Kaiser ,  Engelbert Kloimstein

IPC分类号： C07C51/347

CPC分类号： C07C51/347

摘要： A process for the preparation of color-stable levulinic acid by saponification of acetylsuccinates with aqueous mineral acids, by continuously treating the starting products with steam in counter-current in a reactor cascade, the reaction being carried out above the boiling point of the alcohol being formed in the reaction or above the boiling point of the aqueous azeotrope being formed.

摘要翻译： 通过用无机酸水溶液皂化乙酰琥珀酸盐来制备色稳定乙酰丙酸的方法，通过在反应器级联中以逆流连续处理起始产物，反应在醇的沸点之上进行 形成在反应中或高于所形成的含水共沸物的沸点。

公开(公告)号：US4837335A

公开(公告)日：1989-06-06

申请号：US177345

申请日：1988-04-04

申请人： Hubert Stuckler ,  Wilhelm Dobramysl

发明人： Hubert Stuckler ,  Wilhelm Dobramysl

IPC分类号： C07D231/22

CPC分类号： C07D231/22

摘要： Process for the preparation of pure 1-phenyl-3-carbalkoxy-5-hydroxypyrazoles of the general formula ##STR1## in which R denotes methyl or ethyl, by reaction of acetylsuccinic esters with phenyldiazonium chloride and a base with pK.sub.B value of 3.6 to -1.5 at a pH of 4 to 9 in an aqueous medium to give the corresponding phenylhydrazone, which is cyclized at a pH of 7 to 9.5, with warming and with the addition of ammonia, to give the ammonium salt of the hydroxypyrazole. Compound I is formed by acidification.

摘要翻译： 制备通式（Ⅰ）的纯1-苯基-3-烷氧基-5-羟基吡唑的方法，其中R表示甲基或乙基，通过乙酰基琥珀酸酯与苯基氯化钠的反应和pKB值为 3.6至-1.5，在水性介质中的pH为4至9，得到相应的苯腙，其在pH为7至9.5的条件下加温并加入氨，得到羟基吡唑的铵盐。 化合物I通过酸化形成。