Development of a Practical Synthetic Route of a PDE V Inhibitor KF31327

@inproceedings{Fujino2001DevelopmentOA,
  title={Development of a Practical Synthetic Route of a PDE V Inhibitor KF31327},
  author={Kenji Fujino and Hitoshi Takami and Toshiyuki Atsumi and Takehiro Ogasa and and Shin-ichiro Mohri and Masayoshi Kasai},
  year={2001}
}
An efficient route suitable for a large-scale preparation of KF31327 (1), a potent phosphodiesterase V inhibitor, has been developed. We selected 7-chloro-2,4(1H,3H)-quinazolinedione (15) as a starting material, which gave the desired 6-nitro compound with good selectivity. In the chlorination of 7-ethylamino-6-nitro-2,4(1H,3H)-quinazolinedione (17), reaction conditions were optimized to minimize the amount of phosphorus oxychloride, and 2,4-dichloro-7-ethylamino-6-nitroquinazoline (14) was… CONTINUE READING