4302-89-0

Upstream product

• 1768-31-6 pentachloroacetone 
• 23150-35-8 (R*,R*)-(+)-thiomicamine 
• 872302-03-9 dichloroacetyl-phosphorous acid diethyl ester 
• 535-15-9 ethyl 1,1-dichloroacetate 
• 79-36-7 dichloroacethyl chloride 
• 160751-27-9 (2S,3S)-2-hydroxymethyl-3-(4-methylthiophenyl)-1H-aziridine 
• 160751-26-8 cis-(S_S,2S,3S)-(+)-N-(p-toluenesulfinyl)-2-carbomethoxy-3-(p-methylthiophenyl)aziridine 
• 160751-25-7 (S)-(-)-N-<(p-methylthio)benzylidene>-p-toluenesulfinamide 
• 14172-52-2 (1RS,2RS)-2-amino-1-(4-methylsulfanyl-phenyl)-propane-1,3-diol 
• 23150-33-6 (1RS,2RS)-2-acetylamino-1-(4-methylsulfanyl-phenyl)-propane-1,3-diol 
• 38423-42-6 N-[1-hydroxymethyl-2-(4-methylsulfanyl-phenyl)-2-oxo-ethyl]-acetamide 
• 119293-92-4 (+/-)-2-dichloroacetamido-β-hydroxy-4-methylmercaptopropiophenone 

Downstream Products

• 73231-34-2 Florfenicol 
• 51458-28-7 (1R,2R)-2-amino-1-<4-(methylsulphonyl)phenyl>-1,3-propanediol 
• 847-25-6 (+/-)-Thiamphenicol 
• 15318-45-3 thiamphenicol 

Relevant academic research and scientific papers

Synthesis of 4-sulfur-substituted (2S,3R)-3-phenylserines by enzymatic resolution. Enantionure precursors for thiamphenicol and florfenicol

Enantiomerically pure 4-methylthio- and 4-methylsulfonylsubstitutcd (2S,3R)-3-phenylserines are prepared by enzymatic resolution of the corresponding racemic threo amides using the amidase from Ochrobactrum anthropi NCIMB 40321. The unwanted (2R,3S) enantiomers of the amides are separated from the enantiopure amino acids and easily racemized after Schiff base formation with the corresponding 4-(methylthio)- and 4-(methylsulfonyl)benzaldehyde. The racemization can be combined with the preparation of the racemic amides by aldol reaction under crystallization conditions to yield only the threo isomers. Enantiopure (25,3R)-3-[4-(methylthio)phenyl]serine and (2S,3R)-3-[4-(methylsulfonyl)phenyl]serine are thus obtained in 78% and 62% overall yields starting from the corresponding substituted benzaldehydes. (2S,3A)-3-[4-(Methylthio)phenyl]serine is reduced to (1R,2R)-2-amino-1-[4-(methylthio)phenyl]propane-1,3-diol with NaBH4/H2SO4 and can be used for the synthesis of thiamphenicol and florfenicol.

Asymmetric synthesis using sulfinimines (thiooxime S-oxides)

The addition of diethylaluminum cyanide and the lithium enolate of methyl α-bromoacetate to sulfinimines (thiooxime S-oxides) is highly diastereoselective affording α-amino nitriles and N-sulfinylaziridines, respectively. Hydrolysis of the α-amino nitriles gives α-amino acids in high ee, while hydrolysis of N-sulfinylaziridine carboxylic acids give β-hydroxy-α-amino acids. The latter compounds were transformed into (+)-thiamphenicol, a broad spectrum antibiotic and sphingosine, an important component of the sphingolipids.

Asymmetric synthesis of the antibiotic (+)-thiamphenicol using cis-N-(p-toluenesulfinyl)aziridine 2-carboxylic acids

A concise, highly efficient asymmetric synthesis of aminopropanediol (1R,2R)-(-)-3, precursor to the broad spectrum antibiotics thiamphenicol/florfenicol 1/2, was prepared in two steps from cis-aziridine 2-carboxylic acid (2S,3S)-(-)-5.