PURPOSE: To obtain the title compound which is used as a medicine, because of its hypotensive and cerebral and coronary vasodilative actions, readily in high yield, by intramolecular cyclization of a propionic acid derivative as a starting substance.
CONSTITUTION: A propionic acid derivative of formula I (R1 is lower alkyl, lower alkoxy; R2 is H, lower alkanoyl; R3, R4 are lower alkyl; one of R5 and R6 is lower alkyl, halogen, and the other is H) or its reactive derivative is subjected to intramolecular cyclization reaction in the presence or in the absence of a condensation agent or a deacidification agent in a solvent such as xylene with heat, preferably at 100W180°C to give the compound of formula II. When a free form of the compound of formula I is used, the reaction is preferably carried out in a solvent in the presence of a condensation reagent, while an acid halide is used as a reactive derivative of the compound of formula I, the reaction is preferably effected in the presence of a deacidification agent.
HARADA TSUNEHIRO
NAGASAWA MASAAKI
| JPS59225174A | 1984-12-18 | |||
| JPS61103877A | 1986-05-22 | |||
| JPS60202871A | 1985-10-14 | |||
| JPS61122281A | 1986-06-10 | |||
| JPS60146884A | 1985-08-02 |
Next Patent: PRODUCTION OF 1, 5-BENZOTHIAZEPIN DERIVATIVE