1,721,031 research outputs found
Heterocyclizations under Vilsmeier conditions: an old method with interesting possibilities in drug research.
No full textThe Vilsmeier reaction is well known and widely used in substituting activated hydrogen with a formyl group into a great variety of mols. This reaction is also a powerful synthetic tool used to obtain many heterocycle compds., which may be difficult to reach or at times inaccessible. The more relevant data published in chem. literature in the last ten years and my personal experience are reported in the following with the aim of showing the valuable synthetic potential of this reaction
[Chemical and pharmacological research on pyran derivatives. VI. 2-Dialkylamino-4-oxo-4H-naphto/1,2-b/pyrans and derivatives].
No full textAminonaphthopyranones I (NRR1 = NMe2, NMeEt, NEt2, pyrrolidino, piperidino, R2-R4 = H; NRR1 = NMe2, R2 = Me, OMe, R3 = R4 = H; NRR1 = NMe2, R2 = R4 = H, R3 = NMe2, NEt2) were prepd. by condensing 1-naphthols with RR1NCOCH2CO2Et. Some I were aminomethylated to I (NRR1 = NMe2, NMeEt, NEt2, R2 = R3 = H, R4 = morpholino, piperidino, 4-methylpiperazino). I (R4 = H) showed some anticonvulsant activity
Synthesis of 3-disubstituted 3H-4,1,2-benzothiadiazines and 3-disubstituted 3H-4,1,2-benzothiadiazine 4,4-dioxides
No full text[Study of 1,5-benzodiazepines. II. Synthesis of 2,4-di-(N-alkyl,N-phenyl)amino-3H-1,5-benzodiazepine].
No full textFollowing 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
[Studies on 1,5-benzodiazepine. I. Derivatives of 4-amino-1,5-benzodiazepine].
No full textCondensation 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
Synthesis of new heterocyclic derivatives of retinoids
No full textReaction of α- and β-ionones I and II with dialkylformamide/phosphorus oxychloride affords enamines III (R = Me2N, Et2N) and IV (R = Me2N) along with the expected chloro derivs. III and IV (R = Cl). Reaction of III (R = Me2N) with hydrazines, hydroxylamine and guanidine furnished pyrazole, isoxazole, pyrimidine derivs., e.g. V, showing the potential of these enaminones as key intermediates in the synthesis of synthetic retinoids
Synthesis of 3-substituted 4,1,2-benzothiadiazine 4,4-dioxides and 2 or 3-substituted 1,4-benzothiadiazine 1,1-dioxides
No full text[Chemical and pharmacological research on derivatives of 1H-naphtho(2,1-b)pyran. 3. Synthesis of 2,2'-methylenbis-(1-oxo-3-dialkylamino-1H-naphthol(2,1-b)pyran)].
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