Synthesis of novel coumarin and benzocoumarin derivatives and their biological and photophysical studies

Targeted potent antimicrobial and antitumor oxygen-heterocyclic-based pyran analogues: synthesis and computational studies

The process of creating a series of 3-amino-1-aryl-8-methoxy-1H-benzo[f]chromene-2-carbonitriles (4a-q) involved reacting 6-methoxynaphthalen-2-ol (1), the appropriate aromatic aldehydes (2a-q), and malononitrile (3) in an absolute ethanol/piperidine solution under Ultrasonic irradiation. However, the attempt to create 3-amino-1-aryl-1H-benzo[f]chromene-2,8-dicarbonitrile (6a, d, e) was unsuccessful when 6-cyanonaphthalen-2-ol (5) was stirred at room temperature, reflux, Microwave irradiation, or Ultrasonic irradiation. In addition, the target molecules were screened against Staphylococcus aureus (MRSA), Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Escherichia coli and Klebsiella pneumonia, as well as a panel of three human cancer cells lines such as MCF-7, HCT-116, HepG-2 and two normal cell lines HFL-1 and WI-38. The obtained results confirmed that the pyran derivatives (4 m, i, k) which have a double chlorine at 3,4/2,3/2,5-positions, a single halogen atom 3-Cl/4-Br (4c, e) and a double bromine at 3,5-positions with a single methoxy group at 2-position (4n), of phenyl ring, and, to a lesser extent, other pyran derivatives with monoihalogenated (4a, b, d, f), dihalogenated (4 g, h, j, l) or trisubstituent phenyl ring (4o, p, q). Furthermore, compounds 4b-e, g, i, j, m, and n showed negligible activity against the two normal cell lines, HFL-1 and WI-38. Moreover, compound 4 g exhibited the strongest antimicrobial activity among the other pyran derivatives (4a-f, g-q) when compared to Ciprofloxacin. The MIC was assessed and screened for compound 4 g, revealing bactericidal effects. Lastly, SAR and molecular docking were studied.

Crystal structure of 2-amino-4-(4-meth-oxy-phen-yl)-4H-benzo[g]chromene-3-carbo-nitrile

In the title compound, C21H16N2O2, the naphthalene fragment is twisted slightly, as indicated by the dihedral angle of 3.2 (2)° between the two six-membered rings. The pendant 4-meth-oxy-phenyl ring makes a dihedral angle of 86.08 (6)° with the central six-membered ring of the 4H-benzo[g]chromene ring system. In the crystal, mol-ecules are linked by pairs of N-H⋯N hydrogen bonds, forming inversion dimers which are linked into chains propagating in the b-axis direction by N-H⋯O hydrogen bonds.

An efficient three-component synthesis of coumarin-3-carbamides by use of Ni–NiO nanoparticles as magnetically separable catalyst

An efficient and ecofriendly synthesis of coumarin-3-carbamides has been developed by a three-component reaction of 2-hydroxybenzaldehydes, aliphatic amines (p-/s-) and diethyl malonate using Ni–NiO nanoparticles as catalyst.

N'-[3-Cyano-4-(4-fluoro-phen-yl)-6-meth-oxy-4H-benzo[h]chromen-2-yl]-N,N-dimethyl-methanimidamide

In the title compound, C24H20FN3O2, despite the 4H-pyran ring having a flattened half-chair conformation [the methine C atom lies 0.257 (3) Å above the plane of the remaining atoms with an r.m.s. deviation of 0.0295 Å], the 14 non-H atoms of the 4H-benzo[h]chromene residue are approximately coplanar (r.m.s. deviation = 0.081 Å). The benzene ring is nearly perpendicular to this plane [dihedral angle = 76.18 (10)°], but the planar (r.m.s. deviation = 0.033 Å) dimethyl-methanimidamide substituent is coplanar [dihedral angle = 1.96 (12)°]. In the crystal, centrosymmetric dimeric aggregates arise from C-H⋯N inter-actions, and these are connected into supra-molecular layers in the ab plane by C-H⋯π and π-π [inter-centroid (central C6 ring)⋯(outer C6 ring)(i) distance = 3.8564 (14) Å] inter-actions.

Synthesis, reactions and antimicrobial activities of 8-ethoxycoumarin derivatives

Condensation of 3-acetyl-8-ethoxycoumarin (3) with thiosemicarbazide gave ethylidenehydrazinecarbothioamide 5, which was transformed into the thiazolidin-4-one derivatives 6,7. Interaction of 3 with DMF/POCl₃ gave β-chloroacroline derivative 8. Treatment of 3 with malononitrile gave benzo[c]chromone and 2-aminobenzonitrile derivatives 9 and 10, respectively with respect to the reaction conditions. Condensation of 3-(2-bromoacetyl)-8-ethoxycoumarin (4) with o-phenylenediamine gave 3-(quioxaline-2-yl)-8-ethoxycoumarin hydrobromide (11), while 4 reacted with 2-aminopyridine to give chromenopyridopyrimidine derivative 12. Condensation of 4 with potassium thio-cyanate/methanol gave an unexpected derivative, 2H-chromeno-3-carboxy(methyl-carbonimidic)thioanhydride 16, which upon treatment with (NH₂)₂·H₂O gave 3-ethoxy-2-hydroxybenzaldehyde azine 19. Interaction of 4 with thiourea derivatives gave thiazole derivatives 20a–c. The structures of the newly synthesized compounds were confirmed by their spectra data. The newly synthesized compounds were also screened for their antimicrobial activity.

Synthesis and antimicrobial activities of 2-substituted 12H-chromeno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidines, 3-ethoxycarbonyl-12H-chromeno[3,2-e][1,2,4]triazolo[1,5-c] pyrimidine-2-one and ethyl 2-formylamino- and 2-acetylamino-4H-chromene-3-carboxylates

Preparation of 2-substituted 9-(diethylamino)-12-(4-chlorophenyl)-12 H-chromeno[3,2- e][1,2,4]triazolo[1,5- c]pyrimidines is reported. Furthermore, 3-benzylideneamino-5-(4-chlorophenyl)-8-(diethylamino)-4-imino-3,4-dihydro-5 H-chromeno[2,3- d]pyrimidine, 3-ethoxycarbonyl-12 H-chromeno[3,2- e][1,2,4]triazolo[1,5- c]pyrimidine-2-one, ethyl 2-formylamino- and 2-acetylamino-4 H-chromene-3-carboxylates were prepared. Structures of these compounds were established on the basis of IR, UV, 1H NMR, 13C NMR and MS data. The new compounds were evaluated for antimicrobial activities.

Synthesis of 4H-chromene, coumarin, 12H-chromeno[2,3-d]pyrimidine derivatives and some of their antimicrobial and cytotoxicity activities

Condensation of 3-N,N-diethylaminophenol (1) with α-cyanocinnamonitriles (2a-c) and ethyl α-cyanocinnamates (2d-f) provided compounds 3a-f and 4a-c. 12H-Chromeno[2,3-d]pyrimidine derivatives 6, 11-13 and 16 were obtained by treatment of 4H-chromene compounds (3) with different electrophiles followed by nucleophilic reagents. Structures of these compounds were established on the basis of IR, UV, 1H NMR, 13C NMR and MS data. Some of the new compounds were evaluated for antimicrobial and cytotoxicity activities.