• The Korean Journal of Pesticide Science
• /
• v.9 no.3
• /
• pp.274-277
• /
• 2005

Fenpyroximate was prepared by Williamson synthesis of 4-hydroxyimino-5-phenoxypyrazole and t-butyl 4-bromomethyl benzoate, while an efficient method for the synthesis of t-butyl benzoate still remains a challenging problem. We have found that t-butyl benzoate could be prepared from benzoic acid by the sulfuric acid-catalyzed reaction with isobutene via in situ generation from t-butanol. It has been proven that this process is more convenient for the preparation of t-butyl 4-bromobenzoate, thus allows a facile entry to fenpyroximate.

• Journal of the Korean Chemical Society
• /
• v.31 no.1
• /
• pp.94-97
• /
• 1987

In a converting reaction of $p-bromo-\alpha-diethylaminoacetophenone$ (1a) and $p-bromo-\alpha-piperidinoacetophenone$ (1b) with KCN and $(NH_4)_2CO_3$, to hydantoin, the expected 5-(p-bromophenyl)-5-diethylaminomethylhydantion (2a) and 5-(p-bromophenyl)-5-piperidinomethylhydantoin (2b) were not formed. Diethylaminomethyl group and piperidinomethyl group were eliminated and p,p'-dibromodiphenylhydantil (4), which might be formed through dimerization of 5-(bromophenyl)-hydantoin (3), and p-bromobenzoic acid (5), which was formed through a degradation of 5-(bromophenyl)-hydantoin, were obtained. In the case of $p-bromo-\alpha-morpholinoacetophenone$ (1c), the expected 5-(p-bromophenyl)-5-morpholinomethylhydantoin (2c) was formed.

• YAKHAK HOEJI
• /
• v.52 no.5
• /
• pp.361-369
• /
• 2008

In order to evaluate the cytotoxicity of chromium trioxide, and the cell regenerative effect of phenolic acid against chromium trioxide-induced cytotoxicity, cell viability, cell adhesion activity, lactate dehydrogenase (LDH) activity, and morphological changes of cells were performed in these cultures. The toxicity of chromium trioxide (${IC}_{50}$, 44.0 ${\mu}M$) was high according to the toxic criteria. Cell regeneration of benzoic acid derivatives against ${IC}_{50}$ value of chromium trioxide in cell morphology was increased in concentration-dependent manner. These results suggest that benzoic acid derivatives may be used as a cell regenerative agent against chromium-mediated cytotoxicity.

• Polymer(Korea)
• /
• v.24 no.3
• /
• pp.399-406
• /
• 2000

A thermotropic liquid crystalline polymer (TLCP) containing a flexible spacer was synthesized from hydroquinone, p-hydrofybenzoic acid, and 1,6-dibromohexane. Intercalation of TLCP in layered clays is accomplished by heating the polymer with dodecyl ammonium-montmorillonite (C$_{12}$-MMT) above melt transition temperature (T$_{m}$). Liquid crystallinity of the TLCP/C$_{12}$-MMT hybrid was not observed when $C_{12}$-MMT content was above 1 wt%. Some of the $C_{12}$-MMTs in TLCP were highly dispersed in a nanometer scale, but some of them were agglomerated. Thermal and morphological properties of the nanocomposites were examined by differential scanning calorimetry (DSC), thermogravimetric analyzer (TGA), polarized optical microscope, and electron microscopes (SEM and TEM). TEM).

• Journal of the Korean Applied Science and Technology
• /
• v.22 no.2
• /
• pp.123-135
• /
• 2005

Reaction intermediates PCP/BZA (PBI) and tetramethylene bis(orthophosphate)(TBOP) were synthesized from polycaprolactone (PCP) and benzoic acid (BZA) and from pyrophosphoric acid and 1,4-butanediol, respectively. Benzoic acid modified polyesters containing phosphorus (APTB-S, -10, -15) were synthesized by polycondensation of the prepared PBI (containing 5, 10, 15wt% of benzoic acid), TBOP, adipic acid, and 1,4-butanediol. Network structured PU flame-retardant coatings (APHD) were prepared by curing the synthesized benzoic acid modified polyesters containing phosphorus (APT B - 5 , -10, -15) with hexamethylene diisocyanate (HDI)-timer. From the TGA analysis of APTBs, it was found that the afterglow decreased with the amount of BZA content at the high temperatures. With the introduction of BZA, the film viscosity and film hardness of APHD decreased. With the introduction of caprolactone group, the flexibility, impact resistance, accelerated weathering resistance of APTBs increased. Flame retardancy of the coatings was tested. In a vertical burning method, APHD shows 210$^{\sim}$313 seconds, which indicates that the coatings are good flame-retardant coatings. Moreover, the amount of afterglow and flame retardancy of the coatings are decreased with increasing BZA content.

• The Korean Journal of Pesticide Science
• /
• v.9 no.2
• /
• pp.153-158
• /
• 2005

Safening activities of optically active ${\alpha}$-methylbenzylphenylureas on crop injury of rice (Oryza sativa L., cv. Tsukinohikari, japonica) caused by bensulfuron-methyl (methyl 2-[[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]methyl]benzoate) and pyribenzoxim (benzophenone o-[2,6-bis[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzoyl]oxime) were investigated. Some derivatives of the optically active compounds exhibited strong safening activity against growth inhibition of rice by bensulfuron-methyl. Out of the derivatives tested, (S)-2,3-diCl and (S)-2-F-4-Me derivatives showed greater relieving activity than that of dymuron. In addition, the stress relieving activity was also obtained when they were applied at 4 days after bensulfuron-methyl treatment. On the other hand, crop injury caused by pyribenzoxim was relieved by about 95% with (S)-2-F-4-Me derivative in shoots and roots of rice seedlings.

• Korean Journal of Microbiology
• /
• v.52 no.4
• /
• pp.415-420
• /
• 2016

Chemical study of an Arctic bacterium, Pseudomonas aeruginosa (Pseudomonadaceae) led to the isolation of two diketopiperazines 1 and 2, two phenazine alkaloids 3 and 4, and an indole carbaldehyde 5, along with a benzoic acid derivative 6. The structures of the compounds were confirmed by 1D and 2D NMR, and MS experiments, as well as by comparison of their data with published values. Among the isolates, compounds 5 and 6 were isolated for the first time from P. aeruginosa of the seawater of Arctic Chuckchi Sea. Antimicrobial activities of compounds 1‒6 against a Staphylococcus aureus and Candida albicans were evaluated.

• Polymer(Korea)
• /
• v.26 no.2
• /
• pp.200-208
• /
• 2002

Two-component polyurethane flame-retardant coatings were prepared by blending trichloro lactone modified polyesters (TAPTS) and isocyanate, Desmodur IL. Polycondensation reaction of trichlorobenzoic acid (TBA) as a flame-retardant component, and adipic acid with trimethylolpropane, polycaprolactone 0201, and 1,4-butanediol gave the corresponding TAPTs. The content of TBA was adjusted from 10 to 30 wt% in our experiment. It was found that various properties of these new flame-retardant coatings were comparable to other non-flame-retardant coatings. We also carried out three different tests for the measurement of flammability of flame -retardant coatings. The results of vertical burning test for the coatings containing more than 20 wt% of TBA were determined as 'no burn'. The results of flammability test for the coatings with 20 and 30 wt% of TBA contents indicated the limiting oxygen index (LOI) values of 25% and 27% respectively, which implied relatively good flame retardancy. They also showed the char length of 3.6-5.2 cm according to $45^{\circ}$ Meckel burner test, which can be classified as the first grade flame-retardant coatings.

• Applied Chemistry for Engineering
• /
• v.20 no.2
• /
• pp.177-185
• /
• 2009

The failure analysis of scales deposited on automotive thermostat housing has been carried out. Observations using energy dispersive spectroscopy and electron probe micro analyzer indicate that the main components of scales are some of additives of coolant used. For a detailed investigation of organic matters pyrolysis-GC/MS is employed. The result shows that the main organic component is benzoic acid and furthermore, a small amount of acetophenone, benzene and phenyl group is detected. Based on the results of failure analysis performed, the scales on automotive thermostat housing appear due to the deposition of coolant components, followed by crevice corrosion, into gap between housing and rubber horse. New accelerated test methodology, which could mimic the scale formation and the crevice corrosion on thermostat housing, is developed considering the above results. In order to reproduce the real operating conditions, the accelerating factors, i.e. temperature and humidity, are changed and programmed. The reproducibility of the accelerated test proposed is confirmed after analyzing the scales obtained from the accelerated test.

• Journal of the Korean Chemical Society
• /
• v.17 no.2
• /
• pp.115-121
• /
• 1973

Crystalline products were obtained when$TiCl_4$ was reacted in dichloromethane with acetic, propionic, crotonic, benzoic, furoic and salicylic acids. Chemical analysis has shown that these were all dichlorodicarboxylatotitanium (IV). Cryoscopy of dichlorodipropionatotitanium (IV) indicated the carboxylato-complexes are dimeric. In the IR spectra of these complexes two strong bands both assigned to asymmetric carbonyl stretching vibration have been observed in the region$1500 - 1700cm^{-1}$ and the NMR spectrum of dichlorodipropionatotitanium (IV) has also shown two triplets and two quartets, which indicate that there are two chemically unequivalent carboxylato-ligands in the dimer $[TiCl_2(OOCR)_2]_2$. Their molecular structure was proposed to be bis-carboxo-bridged dimer.