• Journal of the Korean Chemical Society
• /
• v.60 no.4
• /
• pp.251-256
• /
• 2016

This paper describes the synthesis of alkali metal salts of urea (ureates) and their application to the direct preparation of 4-nitrosoaniline from nitrobenzene via nucleophilic aromatic substitution of hydrogen. Sodium and potassium ureates were readily prepared from the reaction of urea with sodium hydride, metal methoxides, and metal hydroxides. The effect of ureates as nucleophiles on the conversion of nitrobenzene to 4-nitrosoaniline was investigated and compared with that of a urea-metal hydroxide mixture. It was found that the ureates were superior for producing 4-nitrosoaniline owing to their higher thermal stability of the ureate. The ureate obtained from the treatment of urea with sodium hydride gave the highest yield for the preparation of 4-nitrosoaniline. The ureates generated from the reaction of urea with metal hydroxide also gave high yields of 4-nitrosoaniline. Catalytic hydrogenation of 4-nitrosoaniline afforded polymer-grade 1,4-benzenediamine in quantitative yield.

• Journal of the Korean Chemical Society
• /
• v.25 no.4
• /
• pp.270-274
• /
• 1981

Al(III) and Cr(III) were determined selectively by colorimetry of Bismark Brown R {4,4'[(4-methyl-1,3-phenylene)bis(azo)]-bis(6-methyl-1,3-benzenediamine) dihydrochloride} in the presence of the various cations and anions without the using of any masking agents, but tartrate and citrate ions were interfered. The ligand of Bismark Brown R and complexes of Al(III) and Cr(III) were shown the maximum absorbance at the same wavelength together and both metallic ion were interfered to determine each other, but Al(III) were able to determine after oxidation of Cr(III) to Cr(VI).

• Journal of the Korean Chemical Society
• /
• v.59 no.2
• /
• pp.132-135
• /
• 2015

Bonding force and stiffness in amine-linked single-molecule junctions for Ag electrodes were measured using a home-built conducting atomic force microscope under ambient conditions at room temperature. For comparison, Au electrodes were used to measure the rupture force and stiffness of the molecular junctions. The traces of the force along with the conductance showed a characteristic saw-tooth pattern owing to the breaking of the metal atomic contacts or the metal-molecule- metal junctions. We found the rupture force and stiffness for Ag are smaller than those for Au electrodes. Furthermore, we observed that the force required to break the amine-Ag bond in the conjugated molecule, 1,4-benzenediamine, is smaller than in 1,4-butanediamine which is fully saturated. These results consist with the previous theoretical calculations for the binding energies of the nitrogen bonded to Ag or Au atoms.

• Korean Journal of Food Science and Technology
• /
• v.28 no.2
• /
• pp.316-323
• /
• 1996

Flavor components in mash of Takju prepared by different raw materials such as nonglutinous rice, glutinous rice, barley and wheat flour were detected by GC and GC-MS method using non-polar column. Seven alcohols, 15 esters, 10 organic acids, 1 aldehyde, 4 benzenes, 3 phenols, 8 alkans, 2 ketones and 5 others were found in takju after 16 day of fermentation. takju by wheat flour had the most various components of volatile flavor. Treatment with addition starter had less flavor component than that without addition starter in takju by nonglutinous rice. Nine kinds of flavor components including acetic acid ethyl ester, 3- methyl-1-butanol, acetic acid, ethyl benzene, acetic acid 3-methyl butyl ester, 2-phenylethanol, 2,6-di-tert-butyl-4-methyl phenol. plumbagic acid and 1,2-benzenedicarboxylic acid dibutyl ester were commonly detected in all the treatments. Especially, 2,4,0-trimethyl-1,3-benzenediamine was isolated in takju that was made of nonglutinous rice without addition starter. Diethyl sulfide, 4-methoxy benzaldehyde, docosane and 2-methyl propyl octadecanoic acid were isolated from takju by nonglutinous rice with addition starter. Propionic acid ethyl ester, acetic acid butyl ester, 2-methyl butane and 3-methyl pentane were isolated from takju glutinous rice. 2-Hydroxy-4-methyl pentanoic acid and 2-methyl tridecane were isolated from akju by barley 3-(Methylthio)-1-propanol. hexanoic acid ethyl ester, butanoic acid monomethyl ester, tridecanoic acid, ethyl tetramethyl cyclopentadiene and 1,5-diaza-2,9-diketocyclotetradecane were isolated from takju by wheat flour. Major volatile flavor components were acetic acid ethyl ester, 3-methyl-1-butanol, acetic acid and 2-phenylethanol.

• Korean Journal of Weed Science
• /
• v.14 no.4
• /
• pp.265-271
• /
• 1994

This study was conducted to determine the herbicidal activity, persistance, downward movement and effect on bentgrass of 7 dinitroaniline herbicides such as benefin [N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl) benzenamine], beslogine [N,N-dibutyl-2,6-dinitro-4-trifluoromethylaniline], prodiamine [2,4-dinitro-$N^3$,$N^3$-dipropyl-6-(trifluoromethyl)-1,3-benzenediamine], pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine], trifluralin [2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl) benzenamine], ethalfluralin [N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl) benzenamine], and oryzalin [4-(diprop-ylamino)-3,5-dinitrobenzene-sulfonamide) together with bensulide [O,O-bis(1-methylethyl) S-[2-[(phenyl-sulfonyl) amino]ethyl]phosphorodithioate] and siduron [N-(2-methylcyclohexyl)-N'-phenylurea) as the control. In addition, distribution of pendimethalin and benefin into bentgrass was also determined. Prodiamine, benefin, and pendimethalin at the 1/16 dose of the recommended rate showed very high herbicidal activity($LD_{90}$) on Digitaria sanguinalis, but ethalfluralin and bensulide showed $LD_{90}$ at the 1/4 dose of the recommended rate, showing difference in herbicidal activities among dinitroaniline herbicides. All the herbicides except for pendimethalin had the lower herbicidal activity in sandy soil than that of clay-loam soil. Benefin, beslogine, prodiamine, oryzalin, bensulide and siduron persisted in the soil for about 50 days, but pendimethalin persisted in the soil for about 35 days, and trifluralin and ethalfluralin for about 25 days. Ethalfluralin, oryzalin and bensulide were the most mobile(downward movement) of the 9 herbicides studied. Less mobility was observed in the turfgrass condition than that of the bare soil. Beslogine bensulide prodiamine and benefin had no injury effect on bentgrass(Agrastis atolonifera L., penncross creeping bent grass). However, herbicides like oryzalin, trifluralin and pendimethalin reduced the dry weight of bentgrass by 12%, 30% and 40%, respectively. No significant difference in distribution of pendimethalin and benefin into inner part of leaves, surface and wax layer of bentgrass was observed, and thus it seems that different phytotoxic effect between pendimethalin and benefin may be attributed to different metabolism and mode of action.