NEW MATERIAL:The heterocyclic compound of formula I (R is lower alkyl; R2 is H or CH3; Y is single bond, CH2 or CH2CH2; the substitution site of 2-hydroxy-3-alkylaminopropoxy group is a- or b-position) and its salt.
EXAMPLE: 3-Methyl-7-[2-hydroxy-3-(isopropylamino)propoxy]benzothiazolone.
USE: A β1-receptor blocking agent having low side effects, almost free from the relaxation-inhibiting action to the bronchus, on the contrary sometimes exhibiting the bronchorelaxing action, having strong activity to cardiac muscle, and giving sufficiently high effect at a low dose.
PREPARATION: The compound of formula I corresponding to the starting materials is obtained either by reacting the compound of formula II [R2' is R2 provided than when Y is H, R2' is not single bond) with the amine of formula R2NH2 or by reacting the compound of formula III with sodium acetate in acetic acid solvent, and refluxing the reaction product in a mixture of hydrochloric acid and ethanol.
NAKAOKU SHIYOUZOU
YOKOIE FUSASHI
YOKOCHI EIJI
