Back to results
US 6,441,201 B1Granted
Method for the preparation of 5-cyanophthalide
AssigneeH. Lundbeck A/S
InventorBeat Weber
Life of this patent
Estimating the term…
Abstract
A method for the preparation of 5-cyanophthalide in which 5-carboxyphthalide is reacted with a dehydrating agent, such as thionylchloride, and a sulphonamide, in particular sulfamide. Cyanophthalide is prepared in high yields by a convenient procedure. 5-cyanophthalide is an intermediate used in the preparation of the antidepressant drug citalopram.
Claims12
A method for the preparation of 5-cyanophthalide
- comprising reaction of 5-carboxyphthalide
- with a dehydrating agent and a sulfonamide of the formula H2N-SO2-R (Formula V) wherein R is
- a) NH2, C1-6 alkyloxy, phenyloxy;
- b) phenyloxy substituted with halogen, C1-4-alkyl, cyano, hydroxy, C1-4-alkoxy, trifluoromethyl, nitro, amino, C1-4-alkylamino or di-C1-4-alkylamino;
- or
- c) phenyl substituted with one or more electron withdrawing substituents.
3 more elements
Dependencies are inferred from the claim text.