申请人:ENICHIMICA SECONDARIA S.p.A.
公开号:EP0127208A1
公开(公告)日:1984-12-05
Preparation of substituted 2,3-dihydrobenzofuran which can be defined by the general formula:
wherein; Ra is hydrogen, halogen, or an alkyl radical, straight lined or branched containing from 1 to 4 carbon atoms, aryl, alkaryl, -OH, -OR3, -N(Ra)2, (Rabeing, in its turn, an alkyl' radical, straight lined or branched containing from 1 to 4 carbon atoms);
Rb is an alkyl radical, straight lined or branched containing from 1 to 6 carbon atoms, aryl or alkaryl;
Rc is hydrogen or has the same meaning as Rb; by rearrangement of 1,1-bis(2-hydroxybenzene)alkyl and/or aryl-ethane, which can be defined by the general formula:
wherein Ra, Rb and Rc have the above specified meanings, working in the presence of catalytic amounts of at least a mineral or an organic acidic compound, at a high temperature and withdrawing from the reaction mass the products of the rearrangement reactions they are being formed.
The 1,1-bis(2-hydroxybenzene)alkyl and/or arylethane are obtained starting from substituted phenols and aldehydes under the influence of specially provided catalysts.
Within the scope of this reaction, 1,1-bis(2,3-dihydroxybenzene)alkyl or aryl-methane are found, which can be defined by the general formula:
wherein: R is an alkyl radical, straight lined or branched, containing from 1 to 20 carbon atoms, or an aryl radical;
R1, R2 and R3 are equal to or different from each other and represent: H, halogen, or the alkyl radical, straight lined or branched, containing from 1 to 4 carbon atoms, aryl, alkaryl, -OH, -OR4,-N(R4)2, R4 being an alkyl radical, straight lined or branched. containing from 1 to 4 carbon atoms.
Such compounds are obtained by reaction of a biphenol which can be defined by the general formula:
with an aldehyde which can be defined by the general formula
wherein R, R,, R2 and R3 have the meanings specified hereinabove, working in the presanca of catalytic amounts of at least one compound, which is a member selected from the group consisting of oxides, hydroxides, alcoholates and carboxylates of the metals belonging to the IA, IIA, IIB and VIIB of the Periodic System of the Eiements, in the presence, or not, of a liquid and inert (i.e. nonreactive) organic solvent, the water being fowned as a reaction byproduct being optionally withdrawn as it is formed.
制备取代的
2,3-二氢苯并呋喃,其通式定义如下
其中;Ra 是氢、卤素、或含有 1 至 4 个碳原子的直链或支链烷基、芳基、烷芳基、-OH、-OR3、-N(Ra)2,(Rabeing 则是含有 1 至 4 个碳原子的直链或支链烷基);
Rb 是含有 1 至 6 个碳原子的直链或支链烷基、芳基或烷芳基;
Rc 是氢或与 Rb 具有相同的含义;通过对 1,1-双(2-羟基苯)烷基和/或芳基
乙烷进行重排,可按通式定义:
其中 Ra、Rb 和 Rc 具有上述特定含义,在催化量至少为矿物或有机酸化合物存在下,在高 温下进行,并从反应物团中抽出正在形成的重排反应产物。
在专门提供的催化剂作用下,可以从取代的
苯酚和醛中获得 1,1-双(2-羟基苯)烷基和/或芳基
乙烷。
在该反应的范围内,可以发现 1,1-双(2,3-二羟基苯)烷基或芳基
甲烷,它们可以用通式来定义:
其中R 是含有 1 至 20 个碳原子的直链或支链烷基或芳基;
R1、R2 和 R3 相等或互不相同,并代表:H、卤素或含有 1 至 4 个碳原子的直链或支链烷基、芳基、烷芳基、-OH、-OR4、-N(R4)2,其中 R4 为含有 1 至 4 个碳原子的直链或支链烷基。
此类化合物是由通式中定义的双
酚与醛反应得到的:
与醛反应而得,醛的定义见通式
其中 R、R、R2 和 R3 的含义如上文所述,在催化剂的作用下,在液体和惰性(即非 反应性)有机溶剂存在或不存在的情况下,至少使用一种化合物,该化合物选自由元素周期 系 IA、IIA、IIB 和 VIIB
金属的氧化物、氢氧化物、醇酸盐和
羧酸盐组成的组。在有或没有液体和惰性(即非反应性)有机溶剂存在的情况下,生成的
水作为反应副产物被抽出。