• Journal of the Korean Chemical Society
• /
• v.45 no.5
• /
• pp.448-453
• /
• 2001

Pyrazoloazines are extremely useful in agriculture and medicine. The main objective of this article is to synthesize some new pyrazoloazines. Ethyl 3-amino-1H-pyrazole-4-carboxylate undergoes diazotization, couples with activated methylene compounds and cyclizes to form pyrazolo[5,1-c][1,2,4]tri-azine derivatives. The title compound also reacts with $\alpha$-substituted cinnamonitriles to produce pyrazolo[1,5-a]pyrimidine derivatives. Structures of newly synthesized compounds are established via chemical and spectral methods.

• Journal of the Korean Chemical Society
• /
• v.36 no.2
• /
• pp.311-317
• /
• 1992

Reaction of 3-alkylidene-2,4-pentanediones(1) with arylhydrazines in methanol afforded 4-acetyl-(2), 4-(1-methoxyalkyl)-(3), or 4-vinylpyrazole derivatives(4). 3-(2,2,2-Trichloroethylidene)-2,4-pentanedione(9) reacted with arylhydrazines to give 4-acetyl-1-aryl-3-methylpyrazoles(11). Possible mechanisms for these reactions were proposed.

• YAKHAK HOEJI
• /
• v.38 no.4
• /
• pp.363-365
• /
• 1994

A series of 6-[2-(3-substituted 4,5-hexamethylenepyrazo-1-yl)ethyl]tetrahydro-4-hydroxy-2H-pyran-2-ones were synthesized from 3-substituted 4,5-hexamethylenepyrazole in 7 steps as potential antihypercholesterolemic agents.

• Journal of the Korean Chemical Society
• /
• v.49 no.4
• /
• pp.377-380
• /
• 2005

• Journal of the Korean Chemical Society
• /
• v.55 no.2
• /
• pp.153-156
• /
• 2011

• Journal of the Korean Chemical Society
• /
• v.46 no.1
• /
• pp.37-45
• /
• 2002

The reaction of 3,6-dichloro-2-(3,5-dimethylpyrazol-1-yl)quinoxaline(8) or 6-chloro-3-hydrazino-2-(3,5-dimethylpyrazol-1-yl)quinoxaline(9) with substituted anilines, sulfa drugs and heteroacyl chlorides gave 2-(pyrazol-1-yl)quinoxalines(10-12). The reaction of compound 9 with alkyl (ethoxymeth-ylene) cyanoacetates resulted in the intramolecular cyclization to give 2,3-di(pyrazol-1-yl)quinoxalines(13).

• Journal of the Korean Chemical Society
• /
• v.55 no.2
• /
• pp.256-261
• /
• 2011

A new series of bis acetylated hybrid pyrazoles were synthesized and characterized by their melting point, elemental analysis, MS, FT-IR, one-dimensional $^1H$, and $^{13}C$ NMR spectroscopic data. All the synthesized compounds were tested for their in vitro antifungal activities against Candida sp. namely Candida albicans, Candida glabrata, Candida parapsilosis, Candida dubliniensis and Candida tropicalis. A close inspection of the in vitro anticandidal activity profile in differently electron donating ($CH_3$ and $OCH_3$) and electron withdrawing (-F, -Cl, and Br) functional group substituted phenyl rings of novel hybrid pyrazoles exerted strong anticandidal activity against all the tested Candida species.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.23 no.7
• /
• pp.539-544
• /
• 2010

We have synthesized new blue electroluminescent polyalkylfluorene-based copolymers [poly(F-co-Py)x:y, where x:y = 99:1 or 95:5 mole ratios] containing the hole-injecting pyrazole derivative [3,3'-(4,6-bis(octyloxy)-1,3-phenylene)bis(1,5-diphenyl-4,5-dihydro-1H-pyrazole] through Ni(0) mediated polymerization, and their electroluminescent properties were investigated. Electroluminescent (EL) devices were fabricated with ITO / PEDOT:PSS (110 nm) / copolymers or PF homopolymer (80 nm) / Ca (50 nm) / Al (200 nm) configuration. Each EL device constructed from the copolymer exhibited significantly enhanced brightness and efficiency compared with a device constructed from the PF homopolymer. The EL device constructed with poly(F-co-Py)99:1 exhibited the highest luminous efficiency and brightness (0.95 cd/A and $2,907\;cd/m^2$, respectively). The achieved luminous efficiency was an excellent result, providing almost a 4-fold improvement on the efficiency obtainable with the a PF homopolymer device. This enhanced efficiency of the copolymer devices results from their improved hole injection and more efficient charge carrier balance, which arises from the HOMO level (~5.83 eV) of the poly(F-co-Py)99:1 copolymer, which is higher than that of the PF homopolyme (~5.90 eV).

• The Korean Journal of Pesticide Science
• /
• v.2 no.3
• /
• pp.117-125
• /
• 1998

Flupyrazofos (O,O-diethyl-O-(1-phenyl-3-trifluoromethyl-5-pyrazoyl)thiophosphoric acid ester) is a new organo-phosphorous insecticide. Flupyrazofos has exhibited excellent activity against diamondback moth (Plutella xylostella, DBM), and it is highly activity against rice armyworm(Pseudaleta separata) and cotton caterpillar(Palpita indicae). Flupyrazofos has then revealed outstanding both rapidity and residual action for DBM, although no systemic actions were observed and no cross-resistances were found to the resistance strains (Op-R, Py-R, IGR-R). Also, susceptibilities of five local strains to flupyrazofos were similar to those of the susceptible strain. These results indicate that flupyrazofos has considerable potential for controlling diamondback moth, rice armyworm and cotton caterpillar in field.

• The Korean Journal of Pesticide Science
• /
• v.9 no.1
• /
• pp.97-101
• /
• 2005

Flupyrazofos (O,O-diethyl O-1-phenyl-3-trifluoromethylpyrazo-5-yl phosphorothioate) is an organophosphorus insecticide with a pyrazole moiety which is newly developed and commercialized by SUNGBO chemical company and Korean Research Institute of Chemical Technology for effectively control against diamond back moth. This study was conducted to determine the composition and quantity of impurities in technical 1 (94.5%), technical 2 (97.6%) and purified (99.2%) flupyrazofos using GLC/MSD. Bimolecular inhibition rate constant($k_i$) with acethylcholinesterase (in vitro) and $I_{50}$ with mouse brain acetylcholinesterase (in vivo) were measured for comparing inhibitory patterns of two technicals and purified flupyrazofos. Impurities of flupyrazofos were identified as O,O,O-triethylthio-phosphoric acid (TEA), 1-phenyl-3-trifluoromethyl-5-ethoxy pyrazole(PTMEP), O,O-diethyl O-1-phenyl-3-trifluoromethylpyrazo-5-yl phosphoric acid ester(flupyrazofos oxen), O,S-diethyl O-1-phenyl-3-trifluoromethylpyrazo-5-yl phosphorothionate (S-ethyl flupyrazofos). In in vitro, technical 1 showed the fastest inhibition on AChE activity among them. And technical 1 and 2 showed 40% higher in vivo inhibition against mouse brian AChE than purified flupyrazofos did. These results could be caused by the impurities such as flupyrazofos oxen and S-methyl flupyrazofos contained in technical grades of flupyrazofos.