(S)-(+)-O-Acetyl-L-mandelic acid

(S)-(+)-O-Acetyl-L-mandelic acid is white to light yellow crystal powde

Recrystallise it from *benzene/hexane or toluene, and it has characteristic NMR and IR spectra. [Pracejus Justus Liebig

Preparation of (S)-2-Acetoxy-2-phenylacetic acid Preparation of (S)-2-acetoxy-2-phenylacetic acid1; To a round bottom flask charged with the Mandelic acid (15 g, 111 mmol) was added 100 mL of acetic anhydride. After 5 min stirring, 10 mL of anhydrous ether was added and followed by a catalytic amount of DMAP. The resultant reaction mixture was kept at r t for additional 16 h. The reaction mixture was evaporated under reduced pressure to give a amorphous material which in turn diluted with EtOAc (50 mL). The solution was washed with 1N HCl (2.x.10 mL), water (2.x.10 mL) and followed by brine solution (10 mL). The org. layer was then dried over MgSOPreparation of (S)-2-acetoxy-2-phenylacetic acid (1) To a round bottom flask charged with the Mandelic acid (15 g, 111 mmol) was added 100 mL of acetic anhydride. After 5 min stirring, 10 mL of anhydrous ether was added and followed by a catalytic amount of DMAP. The resultant reaction mixture was kept at r t for additional 16 h. The reaction mixture was evaporated under reduced pressure to give a amorphous material which in turn diluted with EtOAc (50 mL). The solution was washed with 1N HCl (2.x.10 mL), water (2.x.10 mL) and followed by brine solution (10 mL). The org. layer was then dried over MgSOGeneral procedure: A 25 ml round-bottom flask was charged with Racemic α-hydroxyl acid ester of 0.5 mmol, 10 mLisopropyl ether and immobilized CALB (Novozym 435), the flask was sealed and anhydrous ammonia was added through the solution. The resulting mixture was stirred at 35 °C for a certain time. Samples were taken at 1 h intervals, each time 20 µl of solution were used for analyzing. When the reaction was complete, the solution was filtered through a pad of cotton and the solvent was removed in vacuum. The resulting residues were purified by chromatography on silica gel with petroleum ether–ethyl acetate (1:1 –1:5) to afford the corresponding α-hydroxyl acid, yields and ee values of the desired product were summarized in Table 2.The resolution of (R, S)-mandelic acid was carried out in isopropyl ether containing 300 mM vinyl acetate and 30 mM mandelic acid. The reaction was carried out with shaking at 180 rpm, and was catalyzed by 10 mg/mL (30 U/mL) lipase LC2-8 powder at 30°C. A control reaction was done by performing the above procedure in the absence of enzyme.

(S)-(+)-O-Acetyl-L-mandelic acid is an antibacterial used particularly in the treatment of urinary tract infections.

The (R)- and (S)-isomers are chiral derivatizing agents for NMR determination of enantiomeric purity of α-deuterated carboxylic acids, alcohols, and amines.

Molecular Weight:194.18
XLogP3:1.4
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:4
Exact Mass:194.05790880
Monoisotopic Mass:194.05790880
Topological Polar Surface Area:63.6
Heavy Atom Count:14
Complexity:218
Defined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes