• Title/Summary/Keyword: amines

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A Mechanistic Study on Addition Reactions of Alicyclic Amines to 3-Butyn-2-one

  • 음익환;이정숙;육성민
    • Bulletin of the Korean Chemical Society
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    • v.19 no.7
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    • pp.776-779
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    • 1998
  • Second-order rate constants have been measured spectrophotometrically for the addition reaction of a series of alicyclic amines to 3-butyn-2-one to yield their respective enamines at 25.0 'C. The reactivity of the amines increases with increasing the basicity of the amines. However, the Bronsted-type plot obtained exhibits a downward curvature as the basicity of the amines increases, i.e. βnuc decreases from 0.3 for low basic amines (pKa < 9) and to 0.1 for highly basic amines (pKa > 9). Such a curvature in the Bronsted-type plot is clearly indicative of a change in the reaction mechanism or transition state structure. From the corresponding reactions run in D2O, the magnitude of kinetic isotope effect (KIE) has been calculated to be about 0.8 for highly basic amines and 1.21 for weakly basic amines. The difference in the magnitude of KIE also supports a change in the reaction mechanism or transition state structure upon changing the basicity of the amines. Furthermore, the small KIE clearly suggests that H+ transfer is not involved in the rate-determining step, i.e. the addition reaction is considered to proceed via a stepwise mechanism in which the attack of the amines to the acetylene is the rate-determining step. The curvature in the Bronsted-type plot has been attributed to a change in the degree of bond formation between the amine and the acetylene.

Liquid Phase Adsorption Equilibria of Amines onto High Silica Zeolite, Macroreticular Resin and Granular Activated Carbon (고시리카제올라이트, 거대망상수지 및 입상활성탄에 의한 아민류의 액상흡착평형)

  • Lee, Sung-Sik;Kim, Hyung-Jun;Yu, Myung-Ho
    • Applied Chemistry for Engineering
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    • v.9 no.5
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    • pp.661-666
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    • 1998
  • Liquid phase adsorption equilibria of amines in an aqueous solution onto high silica zeolite pellets (HSZ), macroreticular resin particles (MR) and granular activated carbon (GAC) were determined using a batch bottle technique at 298K. The isotherm curves of HSZ-amines and GAC-amines indicate the nonlinear relationship of unfavorable adsorption type of HSZ-amines and favourable one of GAC-amines. However the curves of MR-amines represent the linear pattern of an adsorption isotherm. Among various equilibrium isotherms, the three parameters of the Redlich-Peterson equation and the two parameters of the Freundlich equation are found to be the most satisfactory within the range of this study. The two parameters of the Langmuir isotherm were not applicable to the present adsorption systems. The amines were adsorbed on the HSZ, MR and GAC in the following sequence of adsorptivity; aromatic amines > primary amines > secondary amines. The product of the Freundlich constants, k and n, proportionally increased with the boiling point, molar volume and dissociation constants of amines adsorbed on HSZ, MR and GAC.

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Ion Pair Extraction of Aliphatic Amines and Quaternary Ammonium Salts by Picric Acid (Picric Acid에 의한 지방족 아민류와 4급 암모늄 염류의 이온쌍 추출)

  • 김박광;이종숙;장성기;나운용;옥치환
    • YAKHAK HOEJI
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    • v.35 no.3
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    • pp.182-189
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    • 1991
  • Systematic study on the extraction of ion pair by the use of picric acid (PCA) as an ion pair forming reagent to the aliphatic amines has not be done by spectrophotometric method. The extraction of ion pair by the use of PCA and 23 kinds of the aliphatic amines was examined. The procedure is as follows; Elving's buffer solution (pH 1.3~10, ionic strength 0.5) each amine solution, and PCA solution were taken into a test tube. The mixture was shaken mechanically with chlorform. The organic phase was filtered through a filter paper to remove water droplets. The absorbance was examined at $\lambda_{max}$ against a reagent blank. Primary and secondary whose carbon number were more than 7 or 6, respectively, are extractable as ion pairs with PCA, while tertiary amines and quaternary ammonium salts are also extractable without the correlation of carbon number. It was considered that the ion pair extraction of primary and secondary amines was affected by the number of carbon of amines, but its extraction of tertiary amines or quaternary ammonium salts was affected by kind of aliphatic amines rather than pKa values or carbon number of amines.

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A Study on the Photoreaction between Organic Halides and Amines (有機 Halides 와 Amines 間의 光反應에 關한 硏究)

  • Kim, You-Sun;Park, Yong-Ja
    • Journal of the Korean Chemical Society
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    • v.6 no.2
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    • pp.148-154
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    • 1962
  • The reactions between organic halides$(CCl_4,\;C_6H_5Br,\;C_6H_5Cl,\;C_6H_5I)$ and amines $(C_6H_5NH_2,\;R_2NH,\;R_3N,\;(CH_2)_5NH,\;pyridine)$ were studied under mixed u.v. irradiation. The modes of reactions were examined by means of gas chromatography and product-reactant ratio determination. The reaction of $CCl_4$ with amines give chloroform and hexachloroethanes, and the reaction of aromatic halides with amines gave biphenyl and benzene. In each series of reaction there obtained mainly corresponding amine hydrohalides, but no amination products. The reactivity was in the order of the basicity of amines and of the reactivity of organic hahides, except in the case of cyclic tertiary amine. The result was interpreted as a non-chain photodecomposition process. A competitive proton abstraction reaction path via the formation of a change transfer complex was proposed as the reaction mechanism.

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Isolation of Biogenic Amines-Degrading Strains of Bacillus subtilis and Bacillus amyloliquefaciens from Traditionally Fermented Soybean Products (전통장류에서 Biogenic Amines 분해 능력을 가지는 Bacillus subtilis 및 Bacillus amyloliquefaciens 균주의 분리)

  • Kim, Yong-Sang;Cho, Sung-Ho;Jeong, Do-Yeon;Uhm, Tai-Boong
    • Korean Journal of Microbiology
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    • v.48 no.3
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    • pp.220-224
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    • 2012
  • In order to reduce harmful biogenic amines in the traditionally fermented soybean products, five isolates with biogenic amines-degrading property were obtained from 83 traditionally fermented soybean products. The strains were found to reduce biogenic amines including histamine, tyramine, putrescine, and cadaverine by 27 to 92% in the cooked soybean containing 5.3% of each biogenic amine over 10 days of incubation. The morphological and biochemical tests and the phylogenetic relationships based on 16S rRNA gene sequences indicated that the five isolates were most closely related to Bacillus subtilis or B. amyloliquefaciens. The use of selected strains would be a potential control measure in manufacturing traditionally fermented soybean products that are difficult to control biogenic amine levels.

t-Butyl Benzotriazol-1-yl Carbonate and Benzyl Benzotriazol-1-yl Carbonate. Now Reactive Amino Protective Reagents for t-Butoxycarbonylation and Benzyloxycarbonylation of Amines and Amino Acids

  • Kim, Sung-Gak;Chang, Heung
    • Bulletin of the Korean Chemical Society
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    • v.7 no.1
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    • pp.70-73
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    • 1986
  • New amino protective reagents, t-butyl benzotriazol-1-yl carbonate and benzyl benzotriazol-1-yl carbonate, for t-butoxycarbonylation and benzyloxycarbonylation of amines and amino acids have been developed. t-Butyl benzotriazol-1-yl carbonate reacts rapidly and cleanly with various amines and amino acids to afford N-Boc amines and N-Boc amino acids in high yields and benzyl benzotriazol-1-yl carbonate is also found to be very effective in the benzyloxycarbonylation of amino acids.

Validation of an HPLC Analytical Method for Determination of Biogenic Amines in Agricultural Products and Monitoring of Biogenic Amines in Korean Fermented Agricultural Products

  • Yoon, Hyeock;Park, Jung Hyuck;Choi, Ari;Hwang, Han-Joon;Mah, Jae-Hyung
    • Toxicological Research
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    • v.31 no.3
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    • pp.299-305
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    • 2015
  • An HPLC analytical method was validated for the quantitative determination of biogenic amines in agricultural products. Four agricultural foods, including apple juice, Juk, corn oil and peanut butter, were selected as food matrices based on their water and fat contents (i.e., non-fatty liquid, non-fatty solid, fatty liquid and fatty solid, respectively). The precision, accuracy, recovery, limit of detection (LOD) and quantification (LOQ) were determined to test the validity of an HPLC procedure for the determination of biogenic amines, including tryptamine, ${\beta}$-phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine and spermine, in each matrix. The LODs and LOQs for the biogenic amines were within the range of 0.01~0.10 mg/kg and 0.02~0.31 mg/kg, respectively. The relative standard deviation (RSD) of intraday for biogenic amine concentrations ranged from 1.86 to 5.95%, whereas the RSD of interday ranged from 2.08 to 5.96%. Of the matrices spiked with biogenic amines, corn oil with tyramine and Juk with putrescine exhibited the least accuracy of 84.85% and recovery rate of 89.63%, respectively, at the lowest concentration (10 mg/kg). Therefore, the validation results fulfilled AOAC criteria and recommendations. Subsequently, the method was applied to the analysis of biogenic amines in fermented agricultural products for a total dietary survey in Korea. Although the results revealed that Korean traditional soy sauce and Doenjang contained relatively high levels of histamine, the amounts are of no concern if these fermented agricultural products serve as condiments.

Application of Two Centre HTEX>$\''{u}$ckel Method for Basicity of the Aliphatic Amines (二中心 H${\u}$ckel 法의 應用 脂肪族 아민의 염기도 [Ⅰ])

  • Byung Kak Park;Mu Sang Lee;Young Suek Hong
    • Journal of the Korean Chemical Society
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    • v.15 no.3
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    • pp.147-152
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    • 1971
  • On the baisis of the calculations by the two centre Huckel method for sigma electron system, the electronic structure of the various aliphatic amines including ammonia, and the relationship between the observed $pK_b$ and the change in the sigma electronic energy, ${\Delta}E{\sigma}$ in the course of protonation are discussed. A parallelism is observed between the $pK_b$ and the calculated ${\Delta}E{\sigma}$ of the amines. Also, it is observed that the electron densities of hydrogen atom directly bonded to nitrogen of the amines, likewise have a linear relationship with the $pK_b$. Therefore, the basicity of the aliphatic amines may be estimated qualitatively by means of the two center Huckel method.

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An Efficient Method for N-Formylation of Amines Using Natural HEU Zeolite at Room Temperature Under Solvent-Free Conditions

  • Bahari, Siavash;Mohammadi-Aghdam, Babak;Mohammad Sajadi, S.;Zeidali, Fereshteh
    • Bulletin of the Korean Chemical Society
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    • v.33 no.7
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    • pp.2251-2254
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    • 2012
  • A rapid and practical green route for N-formylation of primary and secondary amines with formic acid at room temperature under the solvent-free conditions using HEU zeolite as a heterogeneous, reusable and highly efficient catalyst is described. The process is remarkably simple and environmentally benign. Excellent chemoselectivity was observed for the conversion of primary amines in the presence of secondary amines.

Synthesis of ($\pm$)-Methyl-(1-aryl-4-pyridin-3-yl-but-3-enyl)-amines

  • Jang, Jin-Hee;Sin, Kwan-Seog;Park, Hae-Il
    • Archives of Pharmacal Research
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    • v.24 no.6
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    • pp.503-507
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    • 2001
  • trans-Metanicotine, a subtype (${\alpha}_4{\beta}_2$)-selective ligand for neuronal nicotinic acetylcholine receptor, is under clinical phase for Alzheimer's disease. An efficient synthetic route for ($\pm$)-methyl-(1-aryl-4-pyridin-3-yl-but-3-enyl)-am ices, derivatives of tracts-metanicotine, was explored. Allylation reaction of aryl aldimines with allylmagnesium bromide in THF gave ($\pm$)-methyl-(1-aryl-but-3-enyl)-amines. Protection of the amines with the Boc group and following Heck reaction of the N-Boc amines with 3-bromopyridine gave ($\pm$)-methyl-(1-aryl-4-pyridin-3-yl-but-3-enyl)-carbamic acid tert-butyl esters. Deprotection of the N-Boc group in aqueous 1 N-HCI solution gave the titled amines in good yields. Thus, trans-metanicotine analogues modified at the ${\alpha}-position$ of the methylamino group with amyl groups were obtained in 5 steps.

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