Nuevos compuestos derivados de 6,7-dihidro-3 h-oxazolo (3,4-a) pirazina-5,8-diona

COMPUESTOS DERIVADOS DE 6,7-DIHIDRO-3 H-OXAZOLO[3,4-a] PIRAZINA-5,8-DIONA, INHIBIDORES DE FOSFODIESTERASAS; COMPOSICION FARMACEUTICA; USO PARA EL TRATAMIENTO Y/O PROFILAXIS DE DISFUNCION ERECTIL, LITIASIS, HIPERPLASIA PROSTATICA, HIPERTENSION PULMONAR, DISFUNCION SEXUAL, ENTRE OTRAS. The present invention relates to novel derivatives of 6,7-dihydro-3H-oxazolo[3,4-a]pyrazine-5,8-dione, or to a mixture thereof. The present invention also encompasses the pharmaceutical compositions comprising an effective amount of one of said novel compounds of the present invention, as well as to the use of said compounds and/or derivatives as a phosphodiesterase enzyme inhibitor, and the use of the compounds and/or derivatives in the treatment of erectile dysfunction, disorders and/or conditions treatable with relaxation of tissues and disorders treatable with phosphodiesterase inhibitors, more particularly PDE-5 inhibitor. A further objective of the present invention is to provide a medication comprising a therapeutically effective amount of said compound and a method of treatment using the said novel compounds.