17257-71-5 Usage
Chemical Properties
clear colorless viscous liquid
Uses
(S)-(-)-alpha-Methoxy-alpha-(trifluoromethyl)phenylacetic acid is used as a chiral derivatizing agent, it reacts with an alcohol or amine of unknown stereochemistry to form an ester or amide. The absolute configuration of the ester or amide is then determined by proton and/or 19F NMR spectroscopy.
General Description
(S)-(-)-α-Methoxy-α-(trifluoromethyl)phenylacetic acid is commonly used as a derivatizing agent in Mosher ester analysis and Mosher amide analysis, which are NMR-based methods for determining the absolute configuration of the chiral carbon center in secondary alcohols and amines, respectively.
Purification Methods
A likely impurity is phenylethylamine from the resolution. Dissolve the acid in Et2O/*benzene (3:1), wash with 0.5N H2SO4, then water, dry over magnesium sulfate, filter, evaporate and distil it. [Dale et al. J Org Chem 34 2543 1969, J Am Chem Soc 75 512 1973.]
Check Digit Verification of cas no
The CAS Registry Mumber 17257-71-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,7,2,5 and 7 respectively; the second part has 2 digits, 7 and 1 respectively.
Calculate Digit Verification of CAS Registry Number 17257-71:
(7*1)+(6*7)+(5*2)+(4*5)+(3*7)+(2*7)+(1*1)=115
115 % 10 = 5
So 17257-71-5 is a valid CAS Registry Number.
InChI:InChI=1/C10H9F3O3/c1-16-9(8(14)15,10(11,12)13)7-5-3-2-4-6-7/h2-6H,1H3,(H,14,15)/p-1/t9-/m1/s1
17257-71-5Relevant articles and documents
Probing the parallel resolution of Mosher's acid using a combination of quasi-enantiomeric oxazolidin-2-ones
Chavda, Sameer,Coulbeck, Elliot,Dingjan, Marco,Eames, Jason,Motevalli, Majid
, p. 1274 - 1284 (2008/12/20)
Mosher's acid (2-methoxy-2-phenyl-2-trifluoromethylacetic acid) was resolved by parallel resolution of its corresponding pentafluorophenyl active ester using a quasi-enantiomeric combination of oxazolidin-2-ones.
Enantioselective synthesis of arylmethoxyacetic acid derivatives
Moreno-Dorado, F. Javier,Guerra, Francisco M.,Ortega, Maria J.,Zubia, Eva,Massanet, Guillermo M.
, p. 503 - 510 (2007/10/03)
The preparation of several arylmethoxyacetic acids by a sequence of asymmetric dihydroxylation and further oxidation of the resulting glycol with TEMPO/NaClO/NaClO2 is described. The scope and limitations of the reaction are discussed.
An improved synthesis of α-methoxy-α-(trifluoromethyl)-phenylacetic acid (Mosher's acid)
Buszek, Keith R.,Sato, Nagaaki
, p. 488 - 490 (2007/10/03)
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