Process for the preparation of optically active alpha-arylalkanoic acids
申请人:Zambon S.p.A.
公开号:US04697036A1
公开(公告)日:1987-09-29
A new enantioselective process is described for preparing optically active alpha-arylalkanoic acids by: (a) halogenation on the aliphatic carbon atom alpha to the ketal group, of ketals of formula ##STR1## in which Ar represents an aryl, optionally substituted; R represents a C.sub.1 -C.sub.4 alkyl; R.sub.1 and R.sub.2, represents a hydroxy, a O.sup.- M.sup.+, OR.sub.3 or NR.sub.4 R.sub.5 group; the carbon atoms indicated by an asterisk both simultaneously are in (R) or (S) configuration. This reaction is diastereoselective, so that a misture of alpha-haloketals is obtained in which one of the two epimers prevails, and generally strongly prevails, over the other. (b) rearrangement of the haloketals of formula ##STR2## in which X is Cl, Br or I to alpha-arylalkanoic acids in a single stage or in two successive stages, by way of esters of formula ##STR3## The compounds (A) and (C) are all new compounds. The rearrangement step (b) may be performed under new, inventive conditions. The esters of formula (C) have pharmacological activity analogous to that of the corresponding alpha-arylalkanoic acids.
Process for the preparation of optically active alpha-arylalkanoic acids and intermediates thereof
申请人:ZAMBON S.p.A.
公开号:EP0158913A2
公开(公告)日:1985-10-23
A new enantioselective process is described for preparing optically active alpha-arylalkanoic acids by:
a) halogenation on the aliphatic carbon atom alpha to the ketal group, of ketals of formula
in which
Ar represents an aryl, optically substituted;
R represents a C1-C4 alkyl;
R, and R2, represent a hydroxy, a O-M+, OR3 or NR4R5
group; the carbon atoms indicated by an asterisk both
simultaneously are in (R) or (S) configuration.This reaction is
diastereoselective, so that a misture of alpha-haloketals is
obtained in which one of the two epimers prevails, and
generally strongly prevails, over the other.
b) rearrangement of the haloketals of formula
in which X is CI, Br or I to alpha-arylalkanoic acids in a single stage or in two successive stages, by way of esters of formula
The compounds (A) and (C) are all new compounds. The rearrengement step (b) may be performed under new, inventive conditions.
The esters of formula (C) have pharmacological activity analogous to that of the corresponding alpha-arylalkanoic acids.
介绍了一种通过以下方法制备光学活性α-芳基烷酸的对映体选择性新工艺:
a) 卤化式如下的酮的脂肪族碳原子α到酮基
其中
Ar 代表被光学取代的芳基;
R 代表 C1-C4 烷基;
R 和 R2 代表羟基、O-M+、OR3 或 NR4R5。
基团;星号表示的碳原子同时在
该反应具有非对映选择性。
该反应具有非对映选择性,因此可以得到α-卤代金属的畸变体。
该反应具有非对映选择性,因此可以得到α-卤代缩酮的混合物。
该反应具有非对映选择性,因此在得到的α-卤代金属错置物中,两种表聚物中的一种占优势,而且通常比另一种强。
b) 式中α-卤代金属的重排
式中 X 为 CI、Br 或 I 的卤代烃与 α-芳基烷酸在一个阶段或连续两个阶段的重排,通过式中的酯
化合物(A)和(C)均为新化合物。重整步骤 (b) 可在新的创造性条件下进行。
式(C)的酯类具有类似于相应α-芳基烷酸的药理活性。
Process for the preparation of (6-methoxy-2-naphthyl)-(1-bromoethyl)-ketone and its derivatives
申请人:ZAMBON S.p.A.
公开号:EP0203557A1
公开(公告)日:1986-12-03
A process is described for the preparation of (6-methoxy-2-naphthyl)- (1-bromoethyl)-ketone or ketals thereof (I), by selective debromination of (5-bromo-6-methoxy-2-naphthyl) -(1-bromoethyl)- ketone or ketals thereof (III) by means of a bromine acceptor in the presence of an acid and of an inert organic solvent. The bromine acceptor is preferably a phenol, a phenol ether or an aromatic ketone. The acid is preferably a hydrogen halide.
Process for the dehalogenation of naphthalene derivatives
申请人:ZAMBON GROUP S.p.A.
公开号:EP0537558A1
公开(公告)日:1993-04-21
A process for the selective dehalogenation in position 5 of the naphthalenic nucleus of compounds of formula
(wherein X, X₁ and R have the meanings reported in the description) by treatment with a dehalogenating agent selected among hydrogen sulfide, aliphatic thiols or mixtures thereof in an inert anhydrous solvent at acid pH.
一种在式化合物萘核 5 位选择性脱卤的工艺
(其中 X、X₁ 和 R 的含义与描述中所述相同),在酸性 pH 下,在惰性无水溶剂中用硫化氢、脂肪族硫醇或它们的混合物中选出的脱卤剂处理。