S. N. Sirakanyan

Synthesis and Anticonvulsant Activity of Pyrazolo[3,4-b]pyrano(thiopyrano)[4,3-d]pyridine and Pyrazolo[3,4-c]isoquinoline Derivatives

Previously [1 – 3], we reported that pyrano(thiopyrano)[3,4-c]pyridine derivatives possess anticonvulsant properties. At the same time, pyrazolo[3,4-b]pyrano(thiopyrano)[4,3-d]pyridine and pyrazolo[3,4-c]isoquinoline derivatives were never described in the literature. For this reason and in continuation of our work on the search for new biologically active heterocyclic compounds [4, 5], we have developed a method for the synthesis of these condensed compounds, obtained a series of these substances, and studied their anticonvulsant properties. Initial compounds for the synthesis were the previously reported 3-chloro-4-cyano(carbamoyl)pyrano(thiopyrano)[3,4-c]pyridines (Ia – Ig, IIa – IIc) [1 – 3] and 5,6,7,8-tetrahydroisoquinoline derivatives (Ih – In, IId, IIe) obtained by analogous methods. Interacting with hydrazine hydrate, compounds I and II yield tricyclic 1-amino (IIIa – IIIn) and 1-hydroxy (IVa – IVe) derivatives, respectively: R = CN(I), CONH2 (II); I, III: X = O, R = R = CH3 (a); X = O, R = CH3, R 1 = C2H5 (b); X = O, R = CH3, R 1 = iso-C3H7 (c); X = O, R = CH3, R = (d); X = O, R = CH3, R 1 = C6H5 (e); X = S, R = R = CH3 (f); X = S, R = CH3, R 1 = C6H5 (g); X = CH2, R = H, R = CH3 (h); X = CH2, R = H, R 1 = C2H5 (i); X = CH2, R = H, R 1 = C3H7 (j); X = CH2, R = H, R 1 = iso-C3H7 (k); X = CH2, R = H, R 1 = C4H9 (l); X = CH2, R = H, R 1 = (m); X = CH2, R = H, R 1 = C6H5 (n); II, IV: X = O, R = R = CH3 (a); X = O, R = CH3, R 1 = C6H5 (b); X = S, R = R = CH3 (c); X = CH2, R = H, R 1 = C2H5 (d); X = CH2, R = H, R = iso-C3H7 (e).

Synthesis and Anticonvulsive Activity of 7-Amino-Substituted Cyclopenta[4′,5′]-pyrido[3′,2′:4,5]furo[3,2-d]pyrimidines

Methods for the synthesis of new cyclopenta[4′,5′]pyrido[3′,2′:4,5]furo[3,2-d]pyrimidine derivatives based on 3-oxo-derivatives of cyclopenta[c]pyridines were developed. O-alkylated derivatives of these latter compounds were cyclized to furo[2,3-b]pyridines, which were converted to furo[3,2-d]pyrimidin-7-ones with formamide. Subsequent chlorination and amination of 7-oxo derivatives yielded 7-amino derivatives. The anticonvulsive and predicted tranquillizer activities of the compounds synthesized here were assessed. Compounds with anticonvulsant properties were identified.

Synthesis ad Some Conversions of Partially Hydrogenated 1-Aminopyrano(thiopyrano)[4,3-d]pyrazolo[3,4-b]pyridines and Pyrazolo[3,4-c]isoquinolines

We have synthesized derivatives of pyrano(thiopyrano)[4,3-d]pyrazolo[3,4-b]pyridine and pyrazolo[3,4-c]isoquinoline, and we have also carried out some conversions with them.

New heterocyclic systems based on 1-hydrazino-5,6,7,8-tetrahydro[2,7]naphthyridine: 7,8,9,10-tetra-hydro[1,2,4]triazolo[3,4-a]- and 7,8,9,10-tetra-hydro[1,2,4]triazolo[5,1-a][2,7]naphthyridines

Methods have been developed for the synthesis of new substituted 7,8,9,10-tetrahydro[1,2,4]triazolo-[3,4-a][2,7]naphthyridines from 3-chloro-1-hydrazino-7-methyl-5,6,7,8-tetrahydro-[2,7]naphthyridine-4-carbonitrile. It was shown that on heating in an amine (ethanolamine, pyrrolidine, 2-hydroxy-propylamine), they undergo a Dimroth rearrangement at the triazole fragment, being converted into 7,8,9,10-tetrahydro[1,2,4]triazolo[5,1-a][2,7]naphthyridine derivatives.

Synthesis of derivatives of pyrido[2,3-d]pyrimidines condensed with tetrahydropyran and tetrahydrothiopyran

Methods have been developed for obtaining derivatives of W-amino(oxo)-, 8,10-dioxo-, and 10-amino-8-oxo(thio)pyrano(thiopyrano) [4′,3′:4,5]pyrido[2,3-d]pyrimidine on the basis of 3-amino(benzylamino)-4-cyano (carbamoyl)pyrano(thiopyrano)[3,4-c]-pyridines.

Synthesis of derivatives of tetrazolo[1,5-a]- and oxazolo[4,5-b]pyrano(thiopyrano)[3,4-c]pyridines

Tetrazolo[1,5-a]- and oxazolo[4,5-b]pyrano(thiopyrano)[3,4-c]pyridines, which are new heterocyclic systems, have been synthesized from pyrano[3,4-c]pyridine derivatives.

Synthesis and Neurotropic Activity of New 7-Cyclohexyl-6,7,8,9-Tetrahydro-3 H -Pyrazolo[3,4- c ]-2,7-Naphthyridine-1,5-Diamines

A method for synthesizing new tricyclic heterocyclic 7-cyclohexyl-6,7,8,9-tetrahydro-3H-pyrazolo- [3,4-c]-2,7-naphthyridine-1,5-diamines from 1,3-dichloro-7-cyclohexyl-5,6, 7,8-tetrahydro-2,7-naphthyridine-4-carbonitrile was elaborated. Investigation of the biological activity of the synthesized compounds showed that several of them exhibited pronounced neurotropic properties.