Hydrochloric Acid → p-Toluenesulfonic acid
Reaction equation
Cl.O.[C:3]1([CH3:13])[CH:8]=[CH:7][C:6]([S:9]([OH:12])(=[O:11])=[O:10])=[CH:5][CH:4]=1>CO>[C:3]1([CH3:13])[CH:4]=[CH:5][C:6]([S:9]([OH:12])(=[O:10])=[O:11])=[CH:7][CH:8]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 90 °C
Procedure
To 20 mL of methanol, 2.00 g (prepared to be 7.61 mmol) of the hydrochloric acid salt and 1.61 g (8.46 mmol, 1.11 eq) of p-toluenesulfonic acid monohydrate were added, and dissolving under heating was made at 40 to 50° C., followed by making concentration under reduced pressure and drying under vacuum. To the residue, 14 mL of isopropanol and 8 mL of n-heptane were added, and then dissolving was made under heating at 90° C., followed by gradually lowering the temperature to 0° C. The precipitated crystal was filtered, and washed with a small amount of n-heptane, followed by being subjected to drying under vacuum, thereby obtaining 1.71 g of p-toluenesulfonic acid salt (refined product) of α-trifluoromethyl-β-substituted-β-amino acids represented by the above-mentioned formula. The total yield from α-trifluoromethyl-β-substituted-α,β-unsaturated esters was 60%. The diastereomer ratio was syn-body:anti-body=>98:2 according to 1H- and 19F-NMR analyses.
Workup
- dissolutiondissolving
- temperatureunder heating
- customwas made at 40 to 50° C.
- concentrationconcentration under reduced pressure
- customdrying under vacuum
- additionTo the residue, 14 mL of isopropanol and 8 mL of n-heptane were added
- dissolutiondissolving
- customto 0° C
- filtrationThe precipitated crystal was filtered
- washwashed with a small amount of n-heptane
- customto drying under vacuum
Sources & evidence
- ORD record
- ord-67876f0726ba4835b36bcfba42469878
- Source dataset
- uspto-grants-2013_09
- Patent number
- US08524913B2
Reaction notes
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