Method of synthesizing flosequinan from 4-fluoroanthranilic acid
AssigneeR. T. Alamo Venture I LLC
InventorsStephan Kwiatkowski, Maya Siddidqui, Rodney Eisenberg, Sudarsan Mukhopadhyay, Lowell Jeffry Lawrence, Steven G. Mobley
Life of this patent
Estimating the term…
Abstract
A high-yield, 4-step synthesis for flosequinan starting with 4-fluoroanthranilic acid comprising cyclization with phosgene to create an intermediate -A, followed by methylation to create an intermediate -B, then by reaction with dimsyl sodium to create an intermediate -C, then by reaction with triethyl orthoformate in the presence of piperdine and acetic acid to give flosequinan. The overall yield of the disclosed process is greater than about 16%.
Claims8
A process to prepare a compound of formula V comprising the following steps:
- (a) Cyclizing a compound of formula I:
- by reaction with phosgene to give a compound of formula II:
- (b) reacting the product of step (a) with a methylating agent to give a compound of formula III:
- (c) reacting the product of stage (b) with dimsyl sodium to give a compound of formula IV:
- and (d) treating the product of stage (c) with triethyl orthoformate in the presence of piperdine and acetic acid to give the compound of formula V:
Dependencies are inferred from the claim text.