Polyazole systems based on 3,4-dihydroisoquinoline

Synthesis and study of antiinflammatory and analgesic activity of 1-hydrazino-3,3-dialkyl-3,4-dihydroisoquinoline derivatives

“…This result agrees with the previously described interaction of this acid with The reactions of thiolactim esters Ia and Ib with earboxylic acid hydrazides proceed both at room temperature (taking 1 -3 days) and on boiling in methanol (0.5 h), leading to the formation of compounds IVa-We. Heating these compounds in oMichlorobenzene or DMF for 1 -2 h yields substituted triazolo[3, 4-a]isoquinolines Va-Vc [8]. In the case of compound Vb, the intermediate hydrazide exhibit spontaneous cyclization even at room temperature (1 -3 days).…”

“…Compound Va (previously descn'bed in [8]) was obtained in this work by oxidation of compound Ilia in the presence of a five-fold excess of iron(Ill) chloride in boiling ethanol (see the experimental part below)…”

“…For this study we have selected a previously described compound, l-hydrazono-3,3-dimethyl-1,2,3,4-tetrahydroiso quinoline (Ha) [8], and 1-hydrazono-3,3-tetramethylene-I Institute of Technical Chemistry, Ural Division, Russian Academy of Sciences, Perm, Russia. 1,2,3A-tetrahydroisoquinoline (lib) synthesized by a similar procedure.…”

“…The ether was distilled off and the residue recrystallized from ethanol to obtain 0.35 g (80%) of compound Va. Compound Va can be also obtained as described in [8] at a yield of 68%.…”

“…The course of the reactions was monitored and the purity of the synthesized corn- pounds was checked by TLC on Silufol plates eluted with chloroform-acetone (9: 1) mixture; the spots were developed by a 3% chloranyl solution in toluene. hydrazono-3,3-tetramethylene-l,2,3,4-tetrahydrois oquinoline (IIb) was synthesized using a modification of the method described in [8]. According to this modified procedure, a mixture of 2.31 g (10 mmole) of compound Ib and 1.5 g (30 mmole) of hydrazine hydrate in 30 ml of methanol was boiled for 3 h, after which methanol was distilled off.…”