METHOD FOR PREPARING DERIVATIVES OF 2-METHYL-5-(5-METHYL-2-FURYL)-4,10-DIHYDRO-3H-PYRIDAZINO[1,6-b]ISOQUINOLINE-10-ONE (VARIANTS)

FIELD: organic chemistry, chemical technology. ^ SUBSTANCE: invention relates to a method for synthesis of novel derivatives of pyridazino[1,6-b]isoquinolones of the general formula (4a-f): that can be used potential biologically active substances wherein (1a): R1 means hydrogen atom (H); R2 means H; (1b): R1 means chlorine atom (Cl); R2 means H; (1c): R1 means bromine atom (Br); R2 means H; (1d): R1 means iodine atom (J); R2 means H; (1e): R1 means H; R2 means Cl; (1f): R1 means H; R2 means Br. Synthesis is carried out by two variants. The first variant involves carrying out a sequence of three chemical reactions: (A) alkylation reaction of derivatives of 2-di-(5-methyl-2-furyl)methylbenzoic acid with methyl iodide to form corresponding esters; (b) hydrazinolysis reaction of esters to form corresponding hydrazides, and (c) acid-catalyzed recyclization of hydrazides to derivatives of pyridazino[1,6-b]isoquinolone (4a-f). The second variant involves chemical conversion of derivatives of 4-(5-methyl-2-furyl)-3-oxobutylisochromem-1-one to derivatives of pyridazino[1,6-b]isoquinolone (4a-f) by addition of hydrazine hydrate to solution of the corresponding derivative of 4-(5-methyl-2-furyl)-3-oxobutylisochromen-1-one in ethylene glycol medium at room temperature followed by boiling the prepared reaction mixture. ^ EFFECT: improved method of synthesis. ^ 2 cl, 1 tbl, 2 ex