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The photochemical reactions of 1,2,3,4-tetrahydronaphthalene (THN), 9,10-dihydrophenanthrene (DHP), 9,10-dihydroanthracene (DHA), and acenaphthene (AN) with N-bromosuccinimide (NBS) were investigated under N2 atmosphere at room temperature. The results show that the relative reactivities of the hydroarenes toward a photochemical reaction with NBS are THN < DHP < AN << DHA, which is consistent with the stabilities of the radicals produced by benzylic hydrogen abstraction from the hydroarenes. Photochemical reactions of THN and DHP mainly afforded dehydrogenated products, while the photobrominations of the dehydrogenated products from AN and DHA with NBS proceeded readily.

With p-cresol as starting material, 3,4,5-trimethoxybenzaldehyde was synthesized in an overall yield of 67.4% via bromination, hydrolysis, methoxylation and methylation.

Improved and green syntheses of 9,10-diarylacridine-1,8-dione and indenoquinoline derivatives were accomplished by the reactions of 3-anilino-5,5-dimethylcyclohex-2-enones, benzaldehydes, and 1,3-dicarbonyl compounds in the ionic liquid medium [bmim + ][BF 4 - ]. Not only the substituted anilines containing electron-donating groups, but also those with electron-withdrawing groups all gave excellent yields. Furthermore, the interesting unsymmetrical 9,10-diarylacridine-1,8-dione moiety with different groups in the 3- and 6-positions and indenoquinoline derivatives were obtained and are reported here for the first time in the literature. The Knoevenagel condensation and Michael addition intermediates were obtained successfully. A possible mechanism of the reaction is discussed in detail.

An improved and green synthesis of 9-arylacridine-1,8-dione derivatives was accomplished by the reaction of 3-amino-5,5-dimethylcyclohex-2-enone, arylaldehydes and 1,3-dicarbonyl compounds in aqueous medium. Novel unsymmetrical 9-arylacridine-1,8-diones differently substituted at the 3 and 6 positions were obtained by this procedure.

A short and simple synthesis of chromeno[4,3-b]benzo[f]quinoline and quinolino[4,3-b]benzo[f]quinoline derivatives were accomplished in high yields via the reaction of N-benzilidenenaphthalen-2-ami...

In this paper the preparation of 3,3,6,6-tetramethyl-9-aryl-1,2,3,4,5,6,7,8,9,10- decahydroacridin-1,8-dione derivatives from aromatic aldehydes, 5,5-dimethyl-1,3- cyclohexanedione and ammonium acetate in ionic liquids [bmim + ][BF 4 - ] is described. This new method has the advantages of easier work-up, milder reaction conditions, high yields and an environmentally benign procedure compared with other methods.

A series of pyrido[2,3‐d]pyrimidine derivatives were synthesized by the three‐component reaction of arylaldehyde, cyanoacetate, and 4‐amino‐2,6‐dihydroxylpyrimidine in ethyl alcohol at 80°C catalyzed by KF‐Al2O3. It was interesting that further aromatization took place automatically. Compared with other synthetic methods, this new method has the advantage of easier workup, milder reaction conditions, and good yields.

Knoevenagel condensation of malononitrile with aromatic aldehydes can be achieved at room temperature in the absence of catalysts in short time, and the products of arylmethylenemalononitriles were isolated in a practically pure form without further purification.

A series of 1‐oxo‐1,2,3,4,9,10‐hexahydroxanthene derivatives were synthesized from substituted salicylaldehydes and substituted 1,3‐hexanedione in water at 90°C catalyzed by TEBA. The structure of the product was confirmed by X‐ray analysis. Compared with other synthetic methods, this new method has the advantages of easier workup, milder reaction conditions, high yields (85 ∼ 95%) and environmentally benign procedure.

A series of pyrido[2,3‐d]pyrimidine derivatives was synthesized by the reaction of arylaldehyde, malononitrile, and 4‐amino‐2,6‐dihydroxylpyrimidine in ethyl alcohol at 80°C catalyzed by KF‐Al2O3. Compared with other synthetic methods, this new method has the advantage of easier workup, milder reaction conditions, and good yields.

A series of 2‐amino‐3‐cyano‐4‐aryl‐1,4,5,6‐tetrahydropyrano[3,2‐c] quinolin‐5‐one derivatives were synthesized by the reaction of arylaldehyde, malononitrile, and 4‐hydroxyquinolin‐2‐one in ethyl alcohol at 80°C catalyzed by KF–Al2O3. The structure of the product was confirmed by x‐ray analysis.

With (E/Z)-isomeric phytyl halides as side-chain materials, vitamin K 1 is synthesized via a Diels–Alder reaction to activate the free bridgehead hydrogen of 3 for the alkylation and a retro-Diels–Alder reaction to eliminate cyclopentadiene from 2 in a high yield, in which the configuration of the double bond in the phytyl side-chain is retained.

Propinol reacts with dihexylamine by addition–oxidation to give 3-dihexylamino-2-propenal, which is condensed with malononitrile to afford the title product in an overall yield of 73.3%.