Synthesis of newer naphthylpyrazolines, pyrazoles and chalcone epoxides of expected biological activity

N-unsubstituted pyrazolines [IIa-d] were synthesized from the reaction of the chalcones [I] with hydrazine hydrate. The reaction of 2- naphthyl chalcones and hydrazine hydrate in boiling acetic acid gave 1-acetyl-5-aryl-3-[2'-naphthyl]-delta 2-pyrazolines [IIe-h]. Phenyl-, p-tolyl-and p-chlorophenyl-hydrazine reacted with 2-naphthyl chalcones [Ib, d] to give the corresponding 1, 5-diaryl-3-[2'naphthyl]-delta 2- pyrazolines [IIi-o], respectively. Treatment of the 2-naphthyl chalcones [Ia, c, d] with an ethereal diazomethane solution afforded 3-[2'naphthoyl]-4-aryl-delta2-pyrazolines [IIIa-c]. Dehydrogenation of the pyrazolines [IIi-o] to the corresponding 1, 5-diaryl-3-[2'- naphthyl]-pyrazoles [VIa-g] was carried out using tetrachloro- benzoquinone in dry ether. When the 2-naphthylchalcones [Ia-d] in dioxane were allowed to react with hydrogen peroxide in presence of sodium hydroxide, the epoxides [VIIa-d], respectively, were obtained. These compounds are known to have expected pesticidal activity

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

Synthesis of some new-isoxazolines, isoxazoles and-cyclohexen-ones derived from naphthalene of anticipated pesticidal activity

Naphthalenes are known for their widespread biological activity. Also, the pesticidal and antiviral properties have been reported for some cyclohexenone, isoxazoline and isoxazole derivatives. Such a broad spectrum of biological activities prompted us to synthesise some new isoxazolines, isoxazoles and cyclohexenones bearing the naphthalene moiety for biological evaluation. Thus, it is found in the present investigation that when hydroxyl-amine hydrochloride is allowed to react with 3-aryl-l-[2'-naphthyl]-2-propen-1-ones la-d in boiling pyridine; the oximes 2a-d are obtained, respectively, in good yield

Nitrogenous heterocyclic compounds: some new naphthyl-pyrazolines and their dehydrogenation with tetrachloro-obenzoquinone to the corresponding pyrazoles

Compounds: Some New Naphthyl-Pyrazolines and their Dehydrogenation with Tetrachloro-o-benzoquinone to the Corresponding Pyrazoles SEVERAL pyrazoline and pyrazole derivatives are well known for their bactericidal and fungicidal activities. Also, different pyrazoles are now being used as systematic insecticides as well as insecticide stabilizers. Such a broad spectrum biological activities encouraged us to synthesise newer pyrazolines and -pyrazoles derived from naphthalene for biological evaluation. Thus, in the present investigation, it is found that when 3-aryl-l-[2'-naphthyl]-2-propen-l-ones la-d are allowed to react with hydrazine

Newer halo-and hydroxy-aryl pyrazolines and pyrazoles and their infrared spectra

It is found that [la] reacts with one mole of phenylhydrazine in boiling ethanol to give the expected l,3,-diphenyl-5 [3.4-dichlorophenyl]-delta[2]-pyrazoline [2]. The latter is readily dehydrogenated with tetrachloro-o-benzo-quinone at room temperature within a few minutes reaction period to give l,3-diphenyl-5 [3,4-dichlorophenyl] pyrazole[3] in good yield, along with tetra-chlorocatechol in a manner similar to that described by Latif et al. [1], as shown in scheme [A]. Structure of [2] is based on analogy [2-3], analytical data, yellow colour, strong fluorescence characteristic of pyrazolines, as well as spectral features. Its I.R. spectrum lacks nu c=o, nu nh; meanwhile its U.V. spectrum includes two maxima [lambda[max] 245, E 13630; lambda[max]. 350 nm E, 14155 ethanol], and thus supporting the delta[2]- pyrazoline structure [4] and excluding a possible hydrazone formation. The pyrazole[3], in contrast to the parent pyrazoline lacks colour and the absorption in its U.V. spectrum; meanwhile its U.V. spectrum exhibits the expected wave band [lambda[max] 290 nm E, 7390 ethanol] supporting its structure; its I.R. spectrum lacks VG=O and shows VC=N at 1600 cm[-1]. In contrast to the propenone [la], the hydroxyphenyl analogue [Ib] reacts with phenylhydrazine in equimolar amounts under the same conditions to give the expected yellow l,3-diphenyl-5 [3,5-dichloro-2-hydroxyphenyl]-delta[2]-pyrazoline [4a], in addition to the colourless dihydropyrazole [9]. However, when an excess of phenylhydrazine is used, [9] is exclusively produced without possible isolation of [4a]. Structure of [9] is inferred from analytical data, lack of colour and spectral features. Its I.R. spectrum is devoid of nu c=o and includes a broad band in the 3400-3100 cm[-1] region for NH and OH functions. Meanwhile, its U.V. spectrum exhibits a fairly strong styrene like band [[lambda[max]255 nm, E,7580 ethanol] due to the PHC= CH chromophore and lacks long -wave absorption, and thus excluding a delta[2] pyrazoline structure. The production of [9] apparently proceeds through an initial enhanced conjugate addition of the hydrazine to the beta-unsaturated ketone, followed by intramolecular cyclization as shown in scheme [B], which is rather unusual and in contrast to the usual delta[2]-pyrazoline formation which proceeds through the initial 1,2 addition to the carbonyl function