[Neuroleptic properties of Y-20024, a new benzofurancarboxamide derivative].

N-[(1-butyl-2-pyrrolidinyl)methyl]-2-methyl-5-sulfamoyl-2,3- dihydrobenzofuran-7-carboxamide hydrochloride (Y-20024) was synthesized in our laboratories in anticipation of developing a new psychotropic drug. In the present study, the pharmacological properties of Y-20024 were compared with those of sulpiride (SPR) and haloperidol (HPD). Administered orally, Y-20024 was 10 times stronger than SPR in inhibiting apomorphine (0.5 mg/kg, s.c.)-induced hyperactivity in mice; administered intravenously or intracerebroventricularly, it was 2 times or one third as strong, respectively. Y-20024 was almost equipotent to SPR in antagonizing apomorphine (0.1 mg/kg, s.c.)-induced vomiting in dogs. Combined with methamphetamine (5 mg/kg, i.p.), Y-20024 and SPR induced mortality dose-dependently in rats, but HPD did not. The mammotropic activity of Y-20024 administered orally once a day for 5 days was almost equipotent to that of SPR. From these results, Y-20024, pharmacologically similar to SPR, but superior in bioavailability and penetration through the blood brain barrier, may have potential usefulness as an antipsychotic drug.