Methanol → alpha-Methylhydrocinnamic acid
Reaction equation
C[C:2]1[CH:12]=[CH:11][CH:10]=[CH:9][C:3]=1[CH:4]=[CH:5][C:6]([OH:8])=[O:7].[H][H].[CH3:15]O>>[CH3:15][CH:5]([CH2:4][C:3]1[CH:2]=[CH:12][CH:11]=[CH:10][CH:9]=1)[C:6]([OH:8])=[O:7]Participants
Procedure
4.73 mg (0.0126 mmol) of [Rh(NBD)2]BF4 and 12.2 mg (0.0131 mmol) of B1c are placed in a flask provided with a magnetic stirrer and blanketed with argon by repeatedly evacuating the flask and flushing it with argon. 5 ml of degassed methanol are then added and the mixture is stirred for 15 minutes. 0.405 g (2.497 mmol) of 2-methylcinnamic acid and 5 ml of degassed methanol are subsequently introduced into a 10 ml Schlenk flask filled with an argon atmosphere. Stirring is continued until a homogeneous solution is formed. The solution is injected by means of a steel capillary into a 50 ml steel autoclave filled with argon. Finally, 5 bar of hydrogen are introduced in three flushing cycles (argon 20 bar/hydrogen 20 bar). The hydrogenation is started by switching on the stirrer and is carried out at 25° C. The course of the reaction is followed via the hydrogen consumption (pressure decrease in the hydrogen reservoir). After a reaction time of 20 hours, the conversion is found to be complete. The enantiomeric purity of 2-methyl-3-phenylpropionic acid is 81.7% of (R).
Workup
- customprovided with a magnetic stirrer
- customby repeatedly evacuating the flask
- customflushing it with argon
- addition5 ml of degassed methanol are then added
- additionfilled with an argon atmosphere
- stirringStirring
- customis formed
- additionfilled with argon
- customis carried out at 25° C
- customThe course of the reaction is followed via the hydrogen consumption (pressure decrease in the hydrogen reservoir)
- customAfter a reaction time of 20 hours
Sources & evidence
- ORD record
- ord-77d9ed8aa24147bf8c21f3749b913d87
- Source dataset
- uspto-grants-2004_08
- Patent number
- US06777567B2
Reaction notes
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