The reaction of tetralones with nitriles: a simple approach to the synthesis of new substituted benzo[h]quinazolines, benzo[f]quinazolines and dibenzo[a,i]phenanthridines

Significant pharmacological activities of benzoquinazolines scaffold

Benzoquinazolines, the essential constituents of numerous well-known heterocyclic systems, have occupied a prominent position and played a significant part in the synthesis of various pharmaceutical compounds. The wide range of pharmacological effects attributed to benzoquinazolines has been the subject of extensive study. These include their roles as anticancer, antimicrobial, anti-monoamine oxidase, anticonvulsant, antiviral, antinociceptive, antioxidant, antineoplastic, antituberculosis, antiplatelet, and antiphlogistic agents. This work provides an attempt at a literature review of the pharmacological activities of benzoquinazoline derivatives, including an up-to-date account of recent research findings, and suggests avenues for future exploration in the pursuit of more potent and specific analogues for a wide range of biological targets using this platform.

Metal Free Access to Polysubstituted Pyrimidines via Nitrile Activation and [2+2+2] Cycloaddition

Tf₂ O mediated intermolecular / intramolecular [2+2+2] cycloaddition between alkynes and nitriles has been developed for efficient construction of polysubstituted pyrimidines and bicyclopyrimidines. In presence of Tf₂ O, aza-allene species were generated in situ through nitrile activation and subsequently participated in the [2+2+2] cycloaddition, which was fully supported by deuteration experiments. The reaction had good substrate extensibility with moderate to excellent yield including trimethylsilylalkynes. The method was utilized as a synthetic tool in the preparation of a luminescent metal complex.

Synthesis and X-ray crystal structure analysis of 4-(3,4-dichlorophenyl)-2-(3,4,5-trimethoxy-benzylidene)-3,4-dihydro-naphthalen-1(2H)-one: Sertraline key intermediate analog

The novel bioactive compound 4-(3,4-dichlorophenyl)-2-(3,4,5-trimethoxy-benzylidene)-3,4-dihydro-naphthalen-1(2 H)-one was synthesised in three different methods, namely, conventional, MW irradiation with solvent and MW irradiation without solvent. The synthesised compound was characterised by spectroscopic techniques and finally confirmed by X-ray crystal structure analysis.

Crystal structure of (E)-4-benzyl-idene-6-phenyl-1,2,3,4,7,8,9,10-octa-hydro-phenanthridine

The preparation of the title compound, C26H25N, was achieved by the condensation of an ethano-lic mixture of benzaldehyde, cyclo-hexa-none and ammonium acetate in a 2:1:1 molar ratio. There are two crystallographically independent mol-ecules in the asymmetric unit. The two cyclo-hexyl rings adopt an anti-envelope conformation with the benzyl moiety adopting a cis conformation with respect to the nitro-gen atom of the phenanthridine segment. In the crystal, mol-ecules are linked through C-H⋯N inter-actions into hydrogen-bonded chains that are further arranged into distinct layers by weak offset π-π inter-actions.

KOtBu-promoted synthesis of multi-substituted 4-aminopyrimidines from benzonitriles and aliphatic amides

Multi-substituted 4-aminopyrimidines were prepared from commercially-available benzonitriles and aliphatic amides in transition-metal-free conditions. With KO^tBu as the only promoter, target pyrimidines were isolated in moderate to excellent yields.

Synthesis of a series of carbon-14 labeled tetrahydropyrido[4,3-d]pyrimidin-4(3H)-ones

A series of tetrahydropyrido[4,3-d]pyrimidin-4(3H)-ones labeled with carbon-14 in the 2-position of pyrimidinone moiety were prepared as part of a 3-step sequence from benz[amidino-(14) C]amidine hydrochloride as a key synthetic intermediate.

Synthesis of novel 6,6a,7,8-tetrahydro-5H-naphtho[1,2-e]pyrimido[4,5-b][1,4]diazepines under microwave irradiation as potential anti-tumor agents

A new series of 6,6a,7,8-tetrahydro-5H-naphtho[1,2-e]pyrimido[4,5-b][1,4]diazepines 4a-f and 5a-f were efficiently synthesized in good yields from the reaction of E-2-arylidene-1-tetralones 1 and the respective tri- or tetraaminopyrimidines 2 or 3 under microwave irradiation using DMF as solvent and catalytic amounts of BF(3).OEt(2). Six of the obtained compounds were selected and tested by the National Cancer Institute (NCI-USA) against 60 different tumor cell lines. In particular, compounds 5a, 5c and 5e presented remarkable anti-tumor activity against melanoma cancer in SK-MEL-5 cell line.