Carbamic acid, [5-amino-1,2-dihydro-3-[(methylphenylamino)methyl]pyrido-[3,4-b]pyrazin-7-yl]-, ethyl ester, compd. with ethanol (2:1) Carbamic acid, [5-amino-1,2-dihydro-3-[(methylphenylamino)methyl]pyrido[3,4-b]pyrazin-7-yl]-, ethyl ester, compd. with ethanol (2:1) NSC181928