• Korean journal of applied entomology
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• v.40 no.4
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• pp.327-335
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• 2001

In order to establish a whitefly control system using conventional groups of insecticide(carbamate, organophosphorus and pyrethroid insecticides), three alternative application methods were designed on the medium growth stage of cucumber. To discriminate the effectiveness of these sequences observed were the residual activity of insecticides, frequency of insecticide applications, residue of insecticides in cucumber leaves, development of insecticide resistance in whitefly, and yield of fruits. Spraying furathiocarb, a carbamate insecticide, was very effective in reducing the frequency of application for the control of white flies. The effectiveness of furathiocarb was enhanced by the potentiation process to carbofuran, the long residual activity, and the lower development rate of insecticide resistance. Methion, an organophosphorus insecticide, did not show resistance development after successive use but resulted in short residual activity. However, other organophosphates, profenofos and phenthoate, lost their activity by the resistance development. Decreasing activity was common to pyrethroids, deltamethrin and zetacypermethrin due to resistance. From these results it could be drawn a conclusion that furathiocarb, a carbamate insecticide, was the most desirable among conventional insecticide groups for the management of greenhouse whitefly population on the cucumber. To prevent an outbreak of the insect pest by various cause, it was recommended to choose acetamiprid, a nicotinoid, which showed very good control efficacy to the resistance insects to conventional insecticides.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.269-276
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• 2019

A colorimetric rapid detection method based on acetylcholinesterase (AChE) was developed for the analysis of organophosphorus (OP) and carbamate (CB) pesticides. The AChE catalyzes acetylthiocholine into thiocholine having (-) and (+) charges, and the (+) charge results in gold nanoparticle (GNP) aggregation. The in-activation of AChE by OP and CB has been well known. In order to optimize the colorimetric method, optimal dilution times of commercial serum containing AChE, diameter of GNP, and concentration of acetylthiocholine were tested as a key parameter. The colorimetric detection limits of the method were 7.5 ng/mL for both dimethyl amine and carbofuran pesticides in 60% ethanol. No cross-reaction to other chemicals, such as aflatoxin B1 and ochratoxin A, which can be contaminated with pesticides in agricultural products, was observed. Recoveries from lettuce, sesame leaf, and cabbage lettuce spiked with known concentrations of dimethyl amine and carbofuran were found to be ranged from 83.85 to 133.16%. These results indicated that the colorimetric rapid method based on AChE can be a useful tool for the sensitive, specific, rapid, and accurate detection of OP and CB pesticides in fresh vegetables.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.723-728
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• 1998

The chemical behaviours of 4-methyl-2-oxo-2H-benzopyran-7-yl oxoacetyl hydrazine (2) towards some different reagents such as anhydride compounds, aromatic aldehydes, carb on disulphide, and nitrous acid yielded the corresponding pathalazine derivatives (3, 4, 5), hydrazone derivative (6), 1,3,4-oxadiazole derivative (7, 8, 9) and acid azide (10) respectively. Treatmen of 10 with absolute alcohols, amines and ethyl amino acid ester gave the corresponding carbamate derivative (11), substituted urea derivative (12) and ethyl substituted alkyl acetate (13) respectively. The biological activity of some synthesized compounds was evaluated.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2203-2206
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• 2011

A mild and efficient procedure has been developed for the one-pot, three-component reaction of aldehydes, benzyl carbamate and allyltrimethylsilane in the presence of 3 mol % of magnesium bistrifluoromethanesulfonimide at room temperature to afford the corresponding protected homoallylic amines in high yields.

• Archives of Pharmacal Research
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• v.15 no.4
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• pp.333-335
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• 1992

Hofmann rearrangement of a series of primary aliphatic and aromatic carboxamides 1a-1m with HgO-NBS (or dibromantin)R'OH-DMF gives corresponding carbamates 2a-2m in excellent yields.

• Archives of Pharmacal Research
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• v.25 no.1
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• pp.28-38
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• 2002

A series of Schiff's benzimidazole bases, thiosemicarbazides were synthesized, azole ring systems as 1,3,4-triazole, 1,3,4-oxadiazole were prepared. 1-Methylbenzimidazole incorporated to substituted dithio-carbamate, thiophenol, diethylamine via acetamido group were synthesized. A series of pyrimidinobenzimidazoles, triazinobenz-imidazoles, and 2-(acetonylamino)-1-methyl-benzimidazole were prepared. The antimicrobial and molluscicidal activities of some newly prepared compounds were carried out.

• Bulletin of the Korean Chemical Society
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• v.12 no.4
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• pp.373-376
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• 1991

Degradation of (-)-laudanosine, a 1-benzyl-1,2,3,4-tetrahydroisoquinoline alkaloid, with ethyl chloroformate (ECF) afforded an optically active chloro-carbamate as an intermediate. The reason why this intermediate exhibits an optical activity was investigated by comparison with the reactions of some model compounds with ECF. It may be supposed that the chloride group in a hypothetic carbenium ion intermediate stands very closely to the chiral center, so conserving optical activity. However, a neighboring group effect can not be excluded.

• Archives of Pharmacal Research
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• v.26 no.9
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• pp.667-678
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• 2003

We examined the effect of p-substituents in p-substituted cinnamyl methyl ethers and 1-(p-substituted phenyl)allyl methyl ethers with CSI, and confirmed that the CSI reaction of allyl ethers (p-substituted ethers) is a competitive reaction of $S_Ni{\;}and{\;}S_N1$ mechanism according to the stability of the carbocation. And, the only terminal allylic amine was obtained through the migration reaction in thermodynamic reaction condition.

• Polymer(Korea)
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• v.34 no.2
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• pp.144-149
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• 2010

Ag/polystyrene(PS) nanocomposites were prepared by in situ reduction of silver 2-ethylhexylcarbamate (Ag-CB) complex and follwing radical polymerization only by heating at 110 $^{\circ}C$. In contrast to this conventional heating method, the microwave irradiation afforded well-dispersed silver nanoparticles(NPs) in styrene monomer without polymerization. The synthesis of Ag NPs proceeded uniformly throughout the reaction vessel only under microwave irradiation, completing the reaction simultaneously in the whole reaction solution. Successive polymerization of the monomer containing the resultant NPs has successfully produced a hybrid of the silver NPs dispersed in PS matrix. Ag/PS (0.1/100) nanocomposites were prepared successfully by melt-mixing process using Ag/PS(4.0/100) as a master-batch. UV-VIS spectroscopy, TEM, and X-ray diffraction techniques were used to investigate the process of formation of Ag/PS nanocomposites.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.10
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• pp.639-647
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• 2017

This basic study is focused on the physically removal method of carbon dioxide from the decomposition of ammonium carbarmate to prevent the recombination of ammonium salts. A basic visual experimental set-up was designed and constructed to observe the recombination phenomena from the proper composition of ammonia gas, carbon dioxide gas, and compressed air dilution gas. To quantify the recombination phenomena, a simple device was designed to measure the weight change under severe cases for three different tube sizes. The temperature and pressure in the visual tube and the volumetric flow rates of the nitrogen dilution gas were studied and the conditions to avoid recombination were analyzed according to mean free path theory. Diffusivity values based on the Chapman-Enskog theory were calculated from the experimental data. These value may serve as an index for the prevention of recombination.