[EN] PROCESS FOR PREPARING EXTRA PURE 2, 6-DIISOPROPYL PHENOL<br/>[FR] PROCÉDÉ POUR LA PRÉPARATION DE 2,6-DIISOPROPYLPHÉNOL EXTRA PUR
申请人:HARMAN FINOCHEM LTD
公开号:WO2011161687A1
公开(公告)日:2011-12-29
Disclosed herein is a process for the preparation of highly pure 2,6-diisopropyl phenol (Formula I), which comprises reacting p-hydroxy benzoic acid (Formula II) with an alkylating agent in presence of aq. mineral acid followed by basification and subsequent washings to yield 4-hydroxy-3,5-diisopropylbenzoic acid (Formula III) free of dimer impurity, 4, 4'-oxydibenzoic acid of Formula IV, ether impurity 3,5-di(propan-2-yl)-4- (propan-2-yloxy)benzoic acid of Formula V and the monoalkylated impurity 4-hydroxy- 3-(propan-2-yl) benzoic acid of Formula VI; and decarboxylating 4- hydroxy-3,5- diisopropylbenzoic acid (Formula III) in presence of high boiling solvent and sodium hydroxide as a catalyst at high temperature to yield 2, 6-diisopropyl phenol substantially free of ether impurity 1,3-di(propan-2-yl)-2-(propan-2-yloxy)benzene of Formula VII and monoalkylated phenol impurity 2-(propan-2-yl) phenol of Formula VIII. Propofol prepared by the process of the present invention is suitable for pharmaceutical use.
本文公开了一种制备高纯度2,6-二异丙基苯酚(式I)的方法,包括在水矿酸存在下,用烷基化剂与对羟基苯甲酸(式II)反应,然后碱化并进行后续的洗涤,得到不含二聚体杂质、4-羟基-3,5-二异丙基苯甲酸(式III),其中不含乙醚杂质、4,4'-氧二苯甲酸(式IV),乙醚杂质3,5-二(异丙基)-4-(异丙氧基)苯甲酸(式V)和单烷基化杂质4-羟基-3-(异丙基)苯甲酸(式VI);然后在高沸点溶剂和氢氧化钠催化剂的存在下,在高温下脱羧4-羟基-3,5-二异丙基苯甲酸(式III),得到基本不含乙醚杂质1,3-二(异丙基)-2-(异丙氧基)苯(式VII)和单烷基化苯酚杂质2-(异丙基)苯酚(式VIII)的2,6-二异丙基苯酚。使用本发明的方法制备的异丙酚适用于制药用途。