The present invention relates to novel atropisomers of 2-(aryl or heteroaryl)-3-aryl-4(3H)-quinazolinones of the formula I, and their pharmaceutically acceptable salts, and pharmaceutical compositions and methods of treating neurodegenerative and CNS-trauma related conditions.

The present invention relates to novel atropisomers of 3-heteroaryl-4(3H)-quinazolinones of the formula Ia, and their pharmaceutically acceptable salts, and pharmaceutical compositions and methods of treating neurodegenerative and CNS-trauma related conditions.

Compounds of the formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.4 and R.sup.13 are as defined or a pharmaceutically or veterinarily acceptable salt or polymorph thereof, or a pharmaceutically or veterinarily acceptable solvate or pro-drug thereof: are potent and selective inhibitors of type 5 cyclic guanosine 3',5'-monophosphate phosphodiesterase (cGMP PDE5) and have utility in the treatment of, inter alia, male erectile dysfunction (MED) and female sexual dysfunction (FSD).

A process is provide for the preparation of compounds of formula (I) herein ##STR1## comprising reacting a compound of formula (III), (IV) or (V) ##STR2## wherein the variables are as defined in the specification. The reaction is conducted in the presence of .sup.- OR.sup.3 and a hydroxide trapping agent or in the case of compounds of formula (IV) reacting in the presence of an auxiliary base and a hydroxide trapping agent.

A process for the preparation of Compounds of the formula (1): ##STR00001## wherein R.sup.1, R.sup.2, R.sup.4 and R.sup.13 are as defined or a pharmaceutically or veterinarily acceptable salt or polymorph thereof, or a pharmaceutically or veterinarily acceptable solvate or pro-drug thereof: are potent and selective inhibitors of type 5 cyclic guanosine 3',5'-monophosphate phosphodiestbrase (cGMP PDE5) and have utility in the treatment of, inter alia, male erectile dysfunction (MED) and female se...