Newer 1H- 2-pyrazolines and their related derivatives of anticipated biological activity

1 H-delta2-pyrazolines 2 were prepared from the reaction of 2- propen-1-ones 1 with hydrazine hydrate in absolute ethanol at room temperature. Reactions of 2 with acetyl, benzenesulphonyl-, p- toluenesulphonyl-chlorides and ethyl chloroformate gave the corresponding 1-substituted pyrazolines 3 and 4. Compounds 2 reacted also with different isocyanates and isothiocyanates to give carbanilides and thiocarbanilides 5. The pyrazoles 6 were obtained by reaction of the pyrazolines 2 with tetrachloro-O-benzoquinone

New benzopyrans and pyridine derivatives from [2-hydroxyaryl] - propenones

The [2-hydroxyaryl]-propenones [1] react with malononitrile in the presence of piperidine or catalytic amount of potassium hydroxide to give the corresponding benzopyrans. Warming [3] with excess ammonium acetate in absolute ethanol affords the hitherto unknown dihydropyridines [4], whereas, on boiling the propenones [1] with malononitrile in presence of ammonium acetate. Benzopyranopyridines [7] are produced along with the dihydropyridines [4]. [7] could be also obtained by reacting 3- cyano-8-methoxy coumarinimide with the corresponding ketone. Hydrolysis of both benzopyranopyridines [7] and dihydropyridines [4] affords oxo-analogues [8]. Reaction mechanisms have been discussed

New purine derivatives with useful plant-growth regulating properties

The corresponding 6-substituted amino-9-aryl-9H-purines 4a-k are synthesized from reactions of 6-chloro-9-[p-anisyl]-or 9-[p- chlorophenyl]-9H-purines 3c and d with primary amines. Products 4d and k are also obtained by fusing 6-methylthiopurines 5 a and b with benzyl and p-anisyl amines. Most of the products 4a-k have been screened for activity as plant-growth regulating factors for wheat plant. Ring closure of 5-acetylamino 1-arylimidazole-4-carboxamides 6 by methanolic sodium hydroxide solution afforded the corresponding 9-aryl 2-methyl-hypoxantlines 7. The action of phosphoryl chloride on the latter products gave their 6-chloro derivatives 8. Treatment of 8b with p-toludine yielded its 9-[p-anisyl]-2-methyl-6-[p-tolylamino] purine 4 I

Reaction of 1,3-diaryl-2-propene-1-ones with o-Phenylenediamine

The propenones [1a-f] react with o-phenylenediamine in solution to give mainly 2,4-diaryl-2,3-dihydro-1 H-1,5-diazepines [3a-f], respectively, whereas, the analogous propenones [1g-i] afford 2- arylbenzimidazoles. The effect of base catalysis was discussed. The diazepines were also obtained when the components reacted at 120C without a solvent, whereas, at higher temperature 2-arylbenzimidazoles were mainly obtained. Thermolysis of the dihydrodiazepenes afforded 2-arylbenzimidazoles retaining the 4-phenyl ring of the diazepine as the major product together, in some cases, with 2-arylbenzimidazole retaining the 2-substituent