• Korean Journal of Weed Science
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• v.16 no.1
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• pp.36-41
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• 1996

The experiments were conducted to identify the herbicidal effect of 2,4-D{ (2,4-dichlorophenoxy) acetic acid}, 2,4-D ethylester {ethyl 2,4- dichlorophenoxy acetate} and bentazon{3- isopropyl-1H-2,1,3- benzothiazin- 4-(3H)one 2,2-dioxide} on Sagittaria trifolia. Both 2,4-D and 2,4-D ethylester could completely control S. trifolia when applied before 80 days after transplanting of the tubers (DAT), but the weeding effect by bentazone decreased when applied after 60 DAT. 2,4-D and 2,4-D ethylester were effectively translocated from the treated parts to growing point. They killed S. trifolia completely when applied at 80 DAT under 3cm standing water depths, but the controlling effect by bentazone decreased at deeper than 1cm standing water depth. Formation of S. trifolia tuber was effectively suppressed with 2,4-D at 7g ai/10a and 2,4-D ethylester at 6g ai/10a when applied 60 DAT.

• Journal of the Korean Chemical Society
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• v.39 no.5
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• pp.344-349
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• 1995

The crystal and molecular structure of the title compound has been determined from 2568 reflections collected on an automatic CAD4 diffractometer using graphite-monochromated $Mo-K\alpha$ radiation. The crystal is monoclinic system, space group $P2_1$ with unit cell dimensions $a=8.756(8)\AA$, $b=25.757(2)\AA$, $c=8.628(1)\AA$, $\beta=99.15(4)^{\circ}$, V= 1,921(2) ${\AA}^3$, Z=4, $D_C=1.336\;g/cm^3$, ${\mu}=1.54\;cm^{-1}\;and\;T=298^{\circ}K$. The final R factor was 0.051 for 2049 reflections over $3{\sigma}(Fο).$ The crystal has two asymmetric molecules in the unit cell. The arrangement of sulfon group was shown a distorted tetrahedron structure and N(6), N(6') atoms were deviated from the least-squares planes of the thiadiazine rings, respectively. The molecular packings in the unit cell are linked by the two intermolecular hydrogen bonds of N-H---O type and van der Waals forces.

• The Korean Journal of Nuclear Medicine
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• v.33 no.6
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• pp.527-536
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• 1999

Purpose: Radiotracers that bind to the central benzodiazepine receptor are useful for the investigation of various neurological and psychiatric diseases. [C-11]Flumazenil, a benzodiazepine antagonist, is the most widely used radioligand for central benzodiazepine receptor imaging by PET. We synthesized 3-(2-[F-18]fluoro)flumazenil, a new fluorine-18 ($t_{1/2}$= 110 min) labeled analogue of benzodiazepine receptor imaging agent, and evaluated in vivo for biodistribution in mice. Materials and Methods: Flumazenil (Ro 15-1788) was synthesized by a modification of the reported method. Precursor of 3-(2-[F-18]fluoro)flumazenil, the tosylated flumazenil derivative was prepared by the tosylation of the ethyl ester by ditosylethane. [F-18] labeling of tosyl substitued flumazenil precursor was performed by adding F-18 ion at $85^{\circ}C$ in the hot ceil for 20 min. The reaction mixture was trapped by C18 cartridge, washed with 10% ethanol, and eluted by 40% ethanol. Bidistribution in mice was determined after intravenous injection. Results: The total chemical yield of tosylated flumazenil derivative was ${\sim}40%$. The efficiency of labeling 3-(2-[F-18]fluoro)flumazenil was 66% with a total synthesis time of 50 min. Brain uptakes of 3-(2-[F-18]fluoro)flumazenil at 10, 30, 60 min after injection, were $2.5{\pm}0.37,\;2.2{\pm}0.26,\;2.1{\pm}0.11$ and blood activities were $3.7{\pm}0.43,\;3.3{\pm}0.07,\;3.3{\pm}0.09%ID/g$, respectively. Conclusion: We synthesized a tosylated flumazenil derivative which was successfully labeled with no-carrier-added F-18 by nucleophilic substitution.