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.
ketones [ArC(OMe)2CH(OH)Me](Ar = Ph, 4-PhC6H4, 4-BuiC6H4, 4-MeOC6H4, 4-BrC6H4, 6-MeOnaphthalen-2-yl) with diethylaminosulphurtrifluoride (DAST) affords smoothly the methyl 2-arylpropanoates in good yield via aryl-group migration. On the other hand, treatment of aryl 1-hydroxyethyl ketones with DAST gives the corresponding aryl 1-fluoroethyl ketones [ArCOCHFMe](Ar = Ph, 4-PhC6H4, 4-BuiC6H4) in high yield
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。