Potassium Carbonate → Carbamic acid, ethylmethyl-, 3-[1-(dimethylamino)ethyl]phenyl ester
Reaction equation
[CH3:1][N:2]([CH3:12])[CH:3]([C:5]1[CH:6]=[C:7]([OH:11])[CH:8]=[CH:9][CH:10]=1)[CH3:4].[C:13](=[O:16])([O-])[O-].[K+].[K+]>CS(C)=O>[CH3:12][N:2]([CH3:1])[CH:3]([C:5]1[CH:6]=[C:7]([O:11][C:13](=[O:16])[N:2]([CH2:3][CH3:4])[CH3:1])[CH:8]=[CH:9][CH:10]=1)[CH3:4]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
The process of the present invention for example involves reacting 3-[1-(dimethylamino)ethyl]phenol with N-ethyl-N-methyl-4-nitrophenyl carbamate in the presence of potassium carbonate and dimethyl sulfoxide at a temperature ranging from about 80° C. to about 120° C. for about 30 to 40 hours, to form racemate of ethylmethylcarbamic acid 3-[1-(dimethylamino)ethyl]phenyl ester in the free base form. This racemate is then resolved to obtain the (S)-ethylmethylcarbamic acid 3-[1-(dimethylamino)ethyl]phenyl ester. The preferred method of resolution of the (S)-isomer from the racemate involves dissolving a mixture of the free base of the racemate and (+)-di-O, O′-p-toluoyl tartaric acid monohydrate in a 2:1 mixture of methanol:water by heating, collecting the precipitate on cooling by filtration, crystallizing the precipitate from a 2:1 mixture of ethanol:water, and obtaining the substantially pure (S)-isomer by partitioning it between 1N sodium hydroxide and a suitable organic solvent. The base may further be converted to its pharmaceutically acceptable acid addition salts, such as L(+)-tartrate salt.
Sources & evidence
- ORD record
- ord-592b50a1baa545a485225d8154c4dab8
- Source dataset
- uspto-grants-2008_06
- Patent number
- US07385076B2
Reaction notes
Loading…