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Names | |||
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IUPAC names
(R)-3,3,3-trifluoro-2- (S)-3,3,3-trifluoro-2- | |||
Other names Methoxy(trifluoromethyl)phenylacetic acid, MTPA | |||
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ChemSpider | |||
ECHA InfoCard | 100.153.604 | ||
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CompTox Dashboard (EPA) | |||
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Properties | |||
Chemical formula | C10H9F3O3 | ||
Molar mass | 234.17 | ||
Appearance | solid | ||
Melting point | 46 to 49 °C (115 to 120 °F; 319 to 322 K) | ||
Boiling point | 105 to 107 °C (221 to 225 °F; 378 to 380 K) at 1 torr | ||
Hazards | |||
GHS labelling: | |||
Pictograms | |||
Signal word | Warning | ||
Hazard statements | H315, H319, H335 | ||
Precautionary statements | P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501 | ||
Flash point | 110 °C (230 °F; 383 K) | ||
Related compounds | |||
Related acyl chloride | Mosher's acid chloride | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). N verify (what is ?) Infobox references |
Mosher's acid, or α-methoxy-α-trifluoromethylphenylacetic acid (MTPA) is a carboxylic acid which was first used by Harry Stone Mosher as a chiral derivatizing agent. It is a chiral molecule, consisting of R and S enantiomers.
Applications
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 F NMR spectroscopy.
Mosher's acid chloride, the acid chloride form, is sometimes used because it has better reactivity.
See also
References
- J. A. Dale; D. L. Dull; H. S. Mosher (1969). "α-Methoxy-α-trifluoromethylphenylacetic acid, a versatile reagent for the determination of enantiomeric composition of alcohols and amines". Journal of Organic Chemistry. 34 (9): 2543–2549. doi:10.1021/jo01261a013.
- J. A. Dale; H. S. Mosher (1973). "Nuclear magnetic resonance enantiomer regents. Configurational correlations via nuclear magnetic resonance chemical shifts of diastereomeric mandelate, O-methylmandelate, and α-methoxy-α-trifluoromethylphenylacetate (MTPA) esters". Journal of the American Chemical Society. 95 (2): 512–519. doi:10.1021/ja00783a034.
- Y. Goldberg; H. Alper (1992). "A new and simple synthesis of Mosher's acid". Journal of Organic Chemistry. 57 (13): 3731–3732. doi:10.1021/jo00039a043.
- D. L. Dull; H. S. Mosher (1967). "Aberrant rotatory dispersion curves of α-hydroxy- and α-methoxy-α-trifluoromethylphenylacetic acids". Journal of the American Chemical Society. 89 (16): 4230. doi:10.1021/ja00992a053.
- See for example: Mosher Amides: Determining the Absolute Stereochemistry of Optically-Active Amines Allen, Damian A.; Tomaso, Anthony E., Jr.; Priest, Owen P.; Hindson, David F.; Hurlburt, Jamie L. J. Chem. Educ. 2008, 85, 698. Abstract
- D. E. Ward; C. K. Rhee (1991). "A simple method for the microscale preparation of Mosher's acid chloride". Tetrahedron Letters. 32 (49): 7165–7166. doi:10.1016/0040-4039(91)80466-J.