| 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 %. |