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Biomedical subjects

G Roma

Publications and source records attributed to G Roma.

At least 55 records · Page 3Linked to original sources

[Chemical and pharmaceutical research on pyran derivatives. XI. Synthesis of 2-dialkylamino-4-oxo-10-methyl-4H-naphtho[2,3b]pyrans].

Reaction of N,N-dialkylethoxycarbonylacetamides with 1-methyl-2-naphthol, in the presence of phosphorus oxychloride, gave rise to the formation of 2-dialkylamino-4-oxo-10-methyl-4H-naphtho[2,3-b] pyrans through the preliminary attack of the amide-phosphorus oxychloride reactant at the phenolic hydroxyl and cyclization at position 3 of the naphthalene moiety. However when (N-alkyl,N-phenyl)ethoxycarbonylacetamides were used in the reaction an ortho position of the N-phenyl group was involved in the cyclization and 1-alkyl-2(1'-methyl-2'-naphthoxy)-4-quinolones were achieved. Pharmacological investigation showed that some naphtho[2,3-b]pyran derivatives have neurotropic activity of the sedative, anticonvulsant and antidepressant type very similar to that shown by previously studied 1-oxo-3-dialkylamino-1H-naphtho[2,1-b]pyrans (5).

Amphetamine↗

[Chemical and pharmacologic study on pyran derivatives. IX. Synthesis of 2-dialkylaminochromones].

Under suitable conditions the reaction of phenol and N,N-dialkylethoxycarbonylacetamides, in the presence of phosphorus oxychloride, resulted in the formation of 2-dialkylaminochromones. In a similar manner, variously substituted phenols afforded 2-dialkylaminochromones with substituents in different positions of the benzene ring. Pharmacological screening of all these compounds showed that they markedly affect the CNS, activity being mainly excitatory. Decreased activity was shown by compounds with particular substituents in the positions 6,7,8 among which two products [(V e) - K 12440, (V s) - K 12420] have weak but clear anticonvulsant effect.

Animals↗

[Chemical and pharmacological research on pyran derivatives. VII. Derivatives of naphto/1',2':5,6/pyran/2,3-c/pyrazole and of 12H-naphto/1',2':5,6/pyran/2,3-d/pyrimidine].

Reaction of substituted 1-oxo-3-dialkylamino-1H-naphtho[2,1-b]pyrans with N,N-dimethylformamide in the presence of phosphorus oxychloride afforded the corresponding substituted 1-oxo-2-formyl-3-dialkyl-amino-1H-naphtho[2,1-b]pyrans. Condensation of substituted 1-oxo-2-formyl-3-dimethylamino-1H-naphtho[2,1-b]pyrans with hydrazine or monosubstituted hydrazines led to the formation of 11-oxo-8H,11H-naphtho[1',2':5,6]pyrano[2,3-c]pyrazole derivatives through the intermediate hydrazones and subsequent cyclization. Similarly, condensation with acetamidine or guanidine gave rise to the formation of 12-oxo-12H-naphtho[1',2':5,6]pyrano[2,3-d]pyrimidine derivatives. Some of these compounds were tested for their pharmacological properties, but no noteworthy activity was observed.

Animals↗

[Chemical and pharmacological research on pyran derivatives. VIII. Synthesis of 2-dialkylamino-7-methoxychromones and derivatives].

2-Dialkylamino-7-methoxychromones were prepared by reaction of a m-methoxyphenol with N,N-dialkylethoxycarbonylacetamides in the presence of phosphorus oxychloride. Treatment of such compounds with 57% hydriodic acid resulted in the formation of the corresponding 7-hydroxy derivatives. These latter, treated with dialkylamines and formaldehyde, were transformed into the 8-dialkylaminomethyl derivatives. On the other hand the reaction of 2-dialkylamino-7-methoxychromones with morpholine and formaldehyde, in the presence of acetic acid, led to the formation of the corresponding 3-morpholinomethyl derivatives. Pharmacological investigation showed that 2-dialkylamino-7-hydroxy-chromones were without effect, whereas all other compounds tested had a clear, but generally weak, CNS stimulant activity.

Animals↗

[Studies on 1,5-benzodiazepine. I. Derivatives of 4-amino-1,5-benzodiazepine].

Condensation of o-phenylendiamine and N,N-dialkyl-ethoxycarbonylacetamides in the presence of phosphorus oxychloride afforded 2,3-dihydro-2-oxo-4-dialkylamino-1H-1,5-benzodiazepines. These same compounds with a substituent in the 3 position were obtained when N,N-dialkylamino-alpha-ethoxycarbonyl-alpha-alkylacetamides were employed in the reaction. In a similar manner from N-phenyl-o-phenylendiamine the synthesis of 1-phenyl-2,3-dihydro-2-oxo-4-dialkylamino-1H-1,5-benzodiazepines was achieved. The formation of benzimidazole-2-acetic acid derivatives was observed in these reactions.

Amines↗

[Study of 1,5-benzodiazepines. II. Synthesis of 2,4-di-(N-alkyl,N-phenyl)amino-3H-1,5-benzodiazepine].

Following the procedure we described for synthesizing analogous compounds in Note I (7), reaction of N,N-dialkyl or (N-alkyl,N-phenyl)ethoxycarbonylacetamides with 4-chloro-1,2-phenylendiamine, in the presence of phosphorus oxychloride, afforded 2,3-dihydro-2-oxo-4-dialkyl (N-alkyl,N-phenyl)amino-chloro-1H-1,5-benzodiazepines. When a large amount of phosphorus oxychloride was employed in the reaction, the formation of 2,4-di-(N-alkyl,N-phenyl)amino-3H-1,5-benzodiazepines was achieved, starting from suitable o-phenylendiamines and (N-alkyl,N-phenyl)ethoxycarbonylacetamides. Pharmacological tests were carried out on some compounds described in the present paper and on others reported in the preceding Note (7); in this connection 4-amino-1,5-benzodiazepine derivatives showed weak CNS depressing activity in addition, in some cases, to clear, although moderate, anticonvulsant activity, whereas 2,4-diamino-1,5-benzodiazepine derivatives were practically without effect.

Animals↗

[Chemical and pharmacological research on pyran derivatives. VI. 2-Dialkylamino-4-oxo-4H-naphto/1,2-b/pyrans and derivatives].

The 2-dialkylamino-4-oxo-4H-naphtho [1,2-b]pyrans are obtained by the reaction of N,N-dialkylethoxycarbonylacetamides with alpha-naphthol and with substituted alpha-naphthols. The products on treatment with formaldehyde and morpholine or piperidine or N-methylpiperazine are transformed into the 2-dialkylamino-3-dialkylaminomethyl-4-oxo-4H-naphtho [1,2-b]pyrans. Pharmacological investigation has shown that 2-dimethylamino (K 12164), 2-(N-ethyl, N-methyl)amino- (K 12087) and 2-diethylamino-4-oxox-4H-naphtho [1,2-b]pyran (K 12165) show clear neurotropic activity of the neuroleptic type whereas compounds of the isomeric series, 1H-naphtho-[2,1-b]pyrans, studied previously (1), show anticonvulsive and sedative activity. This difference in pharmacological activity has prompted a more complete comparative examination of the activity of the two series of compounds. Study of antagonism to the effects of reserpine by both 4H-naphtho [1,2-b]pyrans and 1H-naphtho [2,1-b]pyrans has shown that in the latter series the 1-oxo-3-dimethylamino- (K 8291), the 1-oxo-3-(N-ethyl, N-methyl)amino- (K 8409) and the 1-oxo-3-diethylamino-1H-naphtho [2,1-b]-pyran (K 8292) have marked neurotropic activity of the antidepressive type.

Antidepressive Agents↗

[Chemical and pharmacological research on derivatives of 1H-naphto/2,1-b/pyran. IV. Substituted 1-oxo-3-dialkylamino-1H-naphto/2,1-b/pyrans].

Reaction of N,N-dialkylethoxycarbonylacetamides with substituted beta-naphthols in 3 or 6 or 7 positions with halogen, alkyl, methoxycarbonyl, methoxyl, ethoxyl in the presence of phosphorus oxychloride, led to the formation of 1-oxo-3-dialkylamino-1H-naphtho[2,1-b]pyrans bearing substituents in 5 or 8 or 9 positions, respectively. Moreover, on account of the chemical nature of such substituents, suitable chemical transformations of these compounds afforded some other 1H-naphtho[2,1-b]pyran derivatives. Pharmacological tests showed that anticonvulsant activity was improved by introduction of methoxy or ethoxy group in 9 position of several 1-oxo-3-dialkylamino-1H-naphtho[2,1-b]pyrans.

Anticonvulsants↗

[Chemical and pharmacological research on derivatives of 1H-naphtho/2,1-b/pyran. V. Behavior of some 1-oxo-3-dialkylamino-1H-naphtho/2,1-b/pyrans substituted in the Mannich reaction].

1-Oxo-3-dialkylamino-1H-naphtho [2,1-b] pyrans substituted in positions 5, 8 or 9 with halogen, alkyl, alkoxycarbonyl, hydroxyl, methoxyl, by the Mannich reaction will yield the corresponding 2-dialkylamino-methyl derivatives when a correct amount of acetic acid is present in the reaction mixture. Excess acid will give rise to the formation of substituted 1-oxo-2-[(1'-oxy-3'-oxo-3'H-naphtho [2',1'-b']pyran-2'-yl)methyl]-3-dialkylamino-1H-naphtho [2,1-b] pyrans when the group in the 3 position is dimethylamino or N-pyrrolidyl. In a few cases Mannich bases were accompanied by an appreciable quantity of substituted 2,2'-methylenebis (1-oxo-3-dialkylamino-1H-naphtho-E12,1-B] PYRANS). Therefore, these compounds were synthesized with excellent yields by treating Mannich bases with acetic anhydride. The behavior of some compounds in the acidic hydrolysis was also considered. Some Mannich bases of 1-oxo-3-dialkylamino-9 methoxy-1H-naphtho-[2,1-b] pyrans showed a more specific anticonvulsant activity than the parent compounds.

Animals↗

1,5-Benzodiazepines. Part XII. Synthesis and biological evaluation of tricyclic and tetracyclic 1,5-benzodiazepine derivatives as nevirapine analogues.

A number of properly substituted 5H-pyrimido[4,5-b][1,5]benzodiazepines (2) and pyrazolo[3,4-b][1,5]benzodiazepines (3 and 4), as well as compounds 5-7, which are derivatives of new tetracyclic systems, were prepared as nevirapine analogues through multistep synthetic routes. The cytotoxic and anti-HIV-1 properties of compounds 2-7 were evaluated in cell-based assays, together with their inhibitory activity against the HIV-1 recombinant reverse transcriptase (rRT) in enzyme assays. The modifications introduced into nevirapine heterocyclic skeleton proved to have a negative effect for the anti-HIV-1 activity. It is worth noting that some of the new derivatives proved to be cytotoxic in the low micromolar range.

Benzodiazepines↗