• Applied Chemistry for Engineering
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• v.33 no.4
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• pp.440-443
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• 2022

A key step in the synthesis of camostat mesylate, which is most widely used as a treatment for chronic pancreatitis, was conducted. Camostat mesylate was synthesized through the esterification reaction of two intermediates, GBA (4-guanidinobenzoic acid hydrochloride) and DOHA [2-(dimethylamino)-2-oxoethyl-2-(4-hydroxyphenyl)acetate]. In order to overcome the problem raised due to the low yield and expensive reagents, a new economical synthesis method was developed that can produce camostat mesylate with a high yield of 80% by activating the acid functional group of GBA using the Vilsmeier-Haack reaction and coupling it with DOHA.

• Bulletin of the Korean Chemical Society
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• v.27 no.1
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• pp.29-30
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• 2006

• Journal of the Korean Society of Propulsion Engineers
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• v.4 no.2
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• pp.1-5
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• 2000

The silane compounds as a coupling agent have been used in the propellant in order to enhance the mechanical property and lower the viscosity. They showed great effects in the PEG propellant. In PCP propellant, however, the silane compounds not only made a severe cure problem but also deteriorated the mechanical property. In this study, TESPN as a silane compound was applied in PEG and PCP binder for finding above factors. The main reason was that the main chains of PCP were broken due to the trans-esterification reaction of ester groups in PCP and alchol which was produced by reacting silane compounds and moisture in the solution of liquid binder.

• Journal of the Korean Chemical Society
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• v.37 no.1
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• pp.136-140
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• 1993

New synthetic method for diethyl N-[4-{[(2,4-diamino-6-yl)methyl]-amino}benzoyl]-L-glutamate(10) which is an intermediate of methotrexate is described. p-Nitrobenzoyl-L-glutamate was obtained via a two-step sequence which involves condensation of p-nitrobenzoyl chloride with diethyl-L-glutamate and Fischer esterification reaction with ethanol. Reductive methylation of diethyl-p-nitrobenzoyl-L-glutamate were carried out by reaction with formic acid and paraformaldehyde in the presence of $PtO_2$ catalyst and yielded diethyl N-(4-methylaminobenzoyl)-L-glutamate(7). It was followed by allylation and iodoazidozation to give the diethyl-p-[N-(2-azido-3-iodopropyl)-N-methyl]aminobenzoyl-L-glutamate(9). The cyclization reaction of compound(9) with 2,4,5,6-tetraaminopyrimidine was carried out by intermolecular nucleophilic substitution to give the desired methotrexate diethylester.

• Clean Technology
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• v.17 no.4
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• pp.325-328
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• 2011

Atom-efficient preparation of 9, 9'-bis[4-(2'-hydroxy-3'-acryloyloxypropoxy) phenyl]fluorene (3), the extensively used building block for fluorene-containing acrylic epoxy polymers has been described. The epoxide ring opening esterification of 9, 9-bis[4-(glycidyloxy)phenyl]fluorene (1) with acrylic acid was catalyzed by some onium salts such as quaternary ammonium and phosphonium salts. While the coupling reactions depend greatly on the kind of the onium salts, the reaction of 9, 9-bis[4-(glycidyloxy)phenyl]fluorene (1) with acrylic acid proceed most efficiently in the presence of a catalytic amount of tetrabutylphosphonium bromide at $110^{\circ}C$ with 90% yield. This reaction is a cleaner reaction that minimizes the use of reactants and the production of chemical wastes.

• Macromolecular Research
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• v.10 no.4
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• pp.204-208
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• 2002

A linear rod-like molecule, bis[4-(1,3-octadynyl)phenyl] terephthalate (2), consisting of two diacetylenic groups, was prepared. The unsymmetric diacetylene was prepared by the Cadiot-Chodkiewicz coupling reaction of 1-bromohexyne with 4-ethynylphenol and linked to a benzene core by an esterification reaction with terephthaloyl chloride in tetrahydrofuran. The thin film (200 nm thickness) of compound 2 was fabricated by the physical vapor deposition on a glass plate with a thermal evaporator. In the X-ray diffraction (XRD) study, the vapor deposited film on the glass plate showed peaks with d spacings of 19.4, 5.7, and 4.5 $\AA$. This XRD pattern was quite different from that observed for compound 2 isolated by recrystallization from methylene chloride/hexane. The vapor deposited film was polymerized by UV irradiation. Photopolymerization was carried out through a photomask, resulting in a patterned image, where the irradiated part became isotropic.