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US 6,207,829 B1Granted
Process for preparation of pyrazolo[4,3-d]pyrimidin-7-ones and intermediates thereof
AssigneePfizer Inc.
InventorsPeter James Dunn, Philip Charles Levett
Life of this patent
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Abstract
A process is provided for the preparation of a compound of formulae (IA) (sidenafil) and (IB) comprising reacting a compound of formula (IIA) and (IIB) respectively in the presence of —OR, wherein R in the case of formation of compound (IA) is CH2CH3 and R in the case of formation of compound (IB) is CH2CH2CH3, where X is a leaving group:
Claims17
A process for the preparation of a compound of formula (IA) or (IB) below:
- comprising reacting a compound of formula (IIA) or (IIB) respectively
- in the presence of —OR, wherein R in the case of formation of compound (IA) is CH2CH3 and R in the case of formation of compound (IB) is CH2CH2CH3, and wherein X is a leaving group.
A process for the preparation of a compound of formula (IA) or (IB) below:
- comprising reacting a compound of formula (IIA) or (IIB) respectively
- in the presence of —OR, wherein R in the case of formation of compound (IA) is CH2CH3 and R in the case of formation of compound (IB) is CH2CH2CH3, or —OR together with an auxiliary base or ZOR together with an auxiliary base wherein ZOR is a salt of —OR and Z is a cation.
Dependencies are inferred from the claim text.