Single-crystal – oriented-crystal – and epitaxy growth processes; – Processes of growth from liquid or supercritical state – Having growth from a solution comprising a solvent which is...
Reexamination Certificate
2007-08-14
2007-08-14
Kunemund, Robert (Department: 1722)
Single-crystal, oriented-crystal, and epitaxy growth processes;
Processes of growth from liquid or supercritical state
Having growth from a solution comprising a solvent which is...
C117S070000, C117S069000, C117S925000, C117S927000
Reexamination Certificate
active
10508529
ABSTRACT:
A method is provided for the isolation of high purity crystalline citalopram (1-[3-dimethylamino)propyl}-1-(4-fluorophenyl)-1, 3-dihydro-5-isobenzofurancarbonitrile) base directly from the alkylation reaction mixture of 5-cyanophthalane with N,N-dimethylaminoprpylchloride in a polar aprotic solvent using a strong base. The method comprises: (a) diluting the reaction mixture with ice cold water and extracting the resulting mixture with a water-immiscible organic solvent; (b) re-extracting the water-immiscible organic solvent extract with an aqueous acid; (c) diluting the aqueous acid extract with a substantially equal volume of a water miscible organic solvent, based on the volume of water in the aqueous acid extract; (d) adjusting the pH to basic with an inorganic base to precipitate free crystalline base and (e) further isolating the precipitated free crystalline base by filration.
REFERENCES:
patent: 4136193 (1979-01-01), Bogeso et al.
patent: 4943590 (1990-07-01), Boegesoe et al.
patent: 2005/0165092 (2005-07-01), Petersen et al.
Babu Ambati Narahari
Gaonkar Santosh Laxman
Goud Vuddamari Srinivas
Kulkarni Ashok Krishna
Manjunatha Sulur G
Jubilant Organosys Limited
Kunemund Robert
Ostrolenk Faber Gerb & Soffen, LLP
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