Synthesis of highly functionalized oxazines by Vilsmeier cyclization of amidoalkyl naphthols

Synthesis and NMR spectral assignments of indol‐3‐yl pyridines through one‐pot multi‐component reaction

“…The 1 H NMR spectrum showed chemical shift of δ = 11.14 ppm (brs, D 2 O exchangeable) which corresponds to -NH proton, and the aromatic protons resonated in the region of δ = 7.23-8.70 ppm. The three sharp distinct peaks appearing in the region of δ = 68.4, 70.0, 71.1, and 82.5 ppm correspond to ferrocenyl ring carbons in the 13 C NMR spectrum and the aromatic carbons appeared in the region of δ = 112.0-162.7 ppm. The mass spectrum displayed the molecular ion [M + H] + peak at m/z 494.20 (Scheme 1)…”

“…[6] The wide-ranging biological activity associated with 3-substituted indoles and pyridines derivatives, both naturally occurring and synthetic, ensures that the synthesis of this important ring system remains a topic of current interest. [7 -10] As part of our ongoing research on the development of novel synthetic routes for the synthesis of biologically active heterocyclic compounds [11 -13] herein, we report the synthesis, [14] 1 H and 13 C NMR spectral assignment of 6-(ferrocene-1-yl)-2-(indol-3-yl)pyridine and (1H-indol-3-yl)-6-(2-thienyl)pyridine derivatives through 2D NMR spectral techniques in solution.…”

Three-Component Synthesis of α-Amidoalkyl-β-naphthols and α-Carbamato-alkyl-β–naphthols Catalyzed by P2O5/SiO2

“…On the other hand, reactions with n-heptaldehyde and noctanaldehyde provided corresponding α-amidoalkyl-β-naphthols with <10% yields, the reactions didn't completed after 24 h and almost 90% of aldehydes were intact without formation aldol condensation products (Table 3, entries 23,24). We also use benzamide instead of acetamide in the mentioned reaction (Table 3, entries [18][19][20][21][22], the α-benzamidoalkyl-β-naphthol derivatives were obtained in excellent yield with short reaction times. The suggested mechanism is described in Scheme 2.…”

Syntheses and transformations of carbamatoalkylnaphthols prepared via modified Mannich reactions

“…13 Since 2006, attention has again focused on the preparation of amido-, carbamido-and carbamatoalkylnaphthol derivatives, since the reaction can be accelerated dramatically by the use of various heterogeneous Lewis and Brønsted acid catalysts. [14][15][16] The importance of these compounds is that they can easily be converted by hydrolysis of the amide and carbamide moieties to aminoalkylnaphthols with potential hypotensive and bradycardiac properties, 17 they can also be transformed to 1,3-oxazine derivatives, and at higher temperatures they yield 1,3-oxazine derivatives with potentially valuable biological activities, e.g. antibiotic, antitumour, analgesic, anticonvulsant, antipsychotic, antimalarial, antianginal, antihypertensive and antirheumatic activities.…”

“…antibiotic, antitumour, analgesic, anticonvulsant, antipsychotic, antimalarial, antianginal, antihypertensive and antirheumatic activities. 16 On the other hand, following deprotection, carbamatoalkylnaphthols can serve as important starting materials for the synthesis of new building blocks with potential pharmacological activities. 18 The literature on the syntheses of amido-, carbamido-and carbamatoalkylnaphthol derivatives will be reviewed.…”