Photochemical rearrangement of α-chloro-propiophenones to α-arylpropanoic acids: studies on chirality transfer and synthesis of (S)-(+)-ibuprofen and (S)-(+)-ketoprofen
作者:Harikisan R. Sonawane、Nanjundiah S. Bellur、Dilip G. Kulkarni、Nagaraj R. Ayyangar
DOI:10.1016/s0040-4020(01)80835-8
日期:1994.1
α-arylpropanoic acids (4) from α chloro-propiophenones (5) is described. It involves carbonyl triplet excited state directed 1,2-aryl migration of the aryl group which has been found to be highly dependent upon the nature of the aryl substituent. The mode of this rearrangement is probed by the study of the photobehaviour of a set of opticallyactive α-chloro-propiophenones. The results suggest that the nature of
A facile one-pot method for the preparation of methyl 2-aryl-propanoates 3 from 2-hydroxypropiophenones dimethyl acetals 1 using sulfuryl chloride, pyridine, and dichloromethane is reported. Yields range from 54 to 87% for the aryl groups: phenyl, 4-bromophenyl, 4-methoxyphenyl, 4-isobutylphenyl, and 4-biphenylyl.
Preparation of Methyl 2-Arylpropanoates by the Reaction of 2-Hydroxypropiophenone Dimethyl Acetals with Sulfuryl Chloride in the Presence of an Amide or a Weak Base
Treatment of 2-hydroxypropiophenone dimethyl acetals [p-RC6H4C(OMe)2CH(OH)Me] (1; R=H, i-Bu, OMe, Ph, Br) with sulfuryl chloride in the presence of an amide or a weak base affords methyl 2-arylpropanoates (2) in good to excellent yields via 1,2-aryl migration of 1. The hydrolysis of 2 leads to the corresponding acids, some of which are pharmaceutically important compounds having nonsteroidal anti-inflammatory
A unique 1,2-shift selectivity in 2-hydroxypropiophenone dimethylacetals: generation of new methodologies for methyl-2-arylpropanoates and 1,2-carbonyl transposition
作者:H.R. Sonawane、B.S. Nanjundiah、D.G. Kulkarni、Jaimala R. Ahuja
DOI:10.1016/s0040-4020(01)86104-4
日期:1988.1
α -Hydroxydimethylacetals I have been shown to undergo two different rearrangements involving highly selective 1,2-shifts under mild conditions. When treated with Ph3P/CCl4, in the presence of pyridine, I were cleanly transformed via 1,2-aryl shifts into methyl 2-arylpropanoates, an important class of anti-inflammatory agents; a pronounced substituent effect has been observed in this rearrangement
已经显示出α-羟基二甲基乙缩醛I在温和条件下经历了两种不同的重排,包括高度选择性的1,2-移位。当用Ph 3 P / CCl 4处理时,在吡啶的存在下,I通过1,2-芳基转移干净地转化为重要的一类抗炎药2-芳基丙酸甲酯;在这种重排中观察到明显的取代作用。
Process for preparing alpha-aromatic group substituted alkanoic acids or esters thereof
申请人:SYNTEX PHARMACEUTICALS
INTERNATIONAL LIMITED
公开号:EP0048136A2
公开(公告)日:1982-03-24
A process for preparing an alpha-aromatic group substituted alkanoic acid or its ester of the general formula
wherein Ar represents an aromatic group and R' represents a hydrogen atom or a saturated aliphatic group, or Ar and R1 may form a condensed ring together with the carbon atom to which they are bonded; and R2 represents a hydrogen atom, an alkyl group, or a hydroxyalkyl group. characterized in that an alpha-sulfonyloxyketone acetal of the general formula
wherein R3 and R4, independently from each other, represent an alkyl group, or taken together, represent an alkylene group; R5 represents a substituted or unsubstituted alkyl group or an aromatic group; and Ar and R1 are as defined above, is hydrolyzed, or treated with an agent having affinity for oxygen: and novel intermediate compounds of the general formula (II) used in aforesaid process.
一种通式为α-芳香族取代的烷酸或其酯的制备方法
其中 Ar 代表芳香族基团,R'代表氢原子或饱和脂肪族基团,或 Ar 和 R1 可与它们所键合的碳原子一起形成缩合环;R2 代表氢原子、烷基或羟烷基。 其特征在于通式的α-磺酰氧基酮缩醛
其中 R3 和 R4 独立地代表一个烷基,或合在一起代表一个亚烷基;R5 代表一个取代或未取代的烷基或芳香基;Ar 和 R1 如上所定义。