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Methyl Benzoate (methyl + benzoate)
Selected AbstractsChemInform Abstract: Convenient N-Formylation of Amines in Dimethylformamide with Methyl Benzoate under Microwave Irradiation.CHEMINFORM, Issue 40 2010Dongsik Yang Abstract Primary and secondary amines are formylated by DMF using methyl benzoate as catalyst. [source] Methyl benzoate as a marker for the detection of mold in indoor building materialsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 18 2005Loay Wady Abstract A convenient analytical method to quantify volatile organic compounds (VOCs) emitted from various building materials has not been addressed yet. This work presents a new and rapid automated method using SPME combined with GC/MS. Methyl benzoate , as a metabolic biomarker for mold growth,was used to indicate VOCs and to determine and assess mold growth on damp samples. Gypsum board and wallboard paper were used as examples of common indoor building materials. Optimized extraction conditions were carried out manually, using a GC/flame ionization detector. Moldy samples were analyzed using an automated SPME-GC/MS analysis under optimized conditions. The amount of methyl benzoate emitted from the studied samples ranged from 32 to 46 ppb, where the density of the fungal biomass was found to be 8×104 cells/mL. A relationship between the amount of fungal biomass and the emitted concentration of methyl benzoate was found and assessed based upon cultured mold samples taken from indoor building sites. The analytical method shows promise for the compound methyl benzoate, which can easily be identified at low detection limits (LOD = 3 ppb) and good linearity (> 0.988), and its extraction and detection can be accomplished cleanly by current extraction techniques. Results suggest that this method with easy sample preparation can be used for quantitation and, of importance, minimal matrix effects are observed. [source] Volatile constituents of benzoin gums: Siam and Sumatra.FLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2003Part Abstract The volatile extract composition of two different benzoin gums, Siam and Sumatra, were analysed by GC,MS. Twenty components representing more than 99.1% of the oil from Siam and 29 components representing more than 97.4% of the oil from Sumatra were analysed. The major components were benzyl benzoate (76.1,80.1%) for the two oils and benzoic acid (12.5%), methyl benzoate (1.5%) and allyl benzoate (1.5%) for Siam, and styrene (2.3%), cinnamic acid (3.5%) and benzyl cinnamate (3.3%) for Sumatra. Volatile compounds of oils and crushed benzoins were also studied using solid-phase microextraction (SPME) employing carboxen/polydimethylsiloxane and carbowax/divinylbenzene ,bres. Copyright © 2003 John Wiley & Sons, Ltd. [source] Preparation of HPLC chiral packing materials using cellulose tris(4-methylbenzoate) for the separation of chrysanthemate isomersJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 17 2006Chiyo Yamamoto Abstract We investigated the separation of chrysanthemate isomers (1), particularly the (1R)-trans form, by high-performance liquid chromatography (HPLC) using polysaccharide derivatives, such as the phenylcarbamates and benzoates of cellulose and amylose, as the chiral stationary phases (CSPs). The chiral packing materials (CPMs) having a high chiral recognition for the chrysanthemic acid ethyl ester (1a) were prepared by coating cellulose tris(4-methylbenzoate) (2a) dissolved in solvents containing methyl benzoate or acetophenone as an additive on silica gel. The separation factor for 1a significantly depended on the preparation conditions of CPM 2a, such as the coating amount of 2a and the type and amount of additives. The chiral recognition ability created by imprinting the additives was lost when the CPM was heated at a high temperature, and was recovered by contacting it with the additive in a packed column. The structural change in 2a during these treatments was not clearly detected by spectroscopic methods. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5087,5097, 2006 [source] Methyl benzoate as a marker for the detection of mold in indoor building materialsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 18 2005Loay Wady Abstract A convenient analytical method to quantify volatile organic compounds (VOCs) emitted from various building materials has not been addressed yet. This work presents a new and rapid automated method using SPME combined with GC/MS. Methyl benzoate , as a metabolic biomarker for mold growth,was used to indicate VOCs and to determine and assess mold growth on damp samples. Gypsum board and wallboard paper were used as examples of common indoor building materials. Optimized extraction conditions were carried out manually, using a GC/flame ionization detector. Moldy samples were analyzed using an automated SPME-GC/MS analysis under optimized conditions. The amount of methyl benzoate emitted from the studied samples ranged from 32 to 46 ppb, where the density of the fungal biomass was found to be 8×104 cells/mL. A relationship between the amount of fungal biomass and the emitted concentration of methyl benzoate was found and assessed based upon cultured mold samples taken from indoor building sites. The analytical method shows promise for the compound methyl benzoate, which can easily be identified at low detection limits (LOD = 3 ppb) and good linearity (> 0.988), and its extraction and detection can be accomplished cleanly by current extraction techniques. Results suggest that this method with easy sample preparation can be used for quantitation and, of importance, minimal matrix effects are observed. [source] Overexpression of the apple alcohol acyltransferase gene alters the profile of volatile blends in transgenic tobacco leavesPHYSIOLOGIA PLANTARUM, Issue 3 2008Dapeng Li Alcohol acyltransferases (AATs) are key enzymes in ester biosynthesis. Previous studies have found that AAT may be a stress-related gene. To investigate further the function of the apple alcohol acyltransferase gene (MdAAT2), transgenic tobacco plants overexpressing MdAAT2 were generated. Gas chromatography,mass spectroscopy analysis showed that the volatile blends were altered in these transgenic tobacco leaves. Although no apple-fruity volatile esters were detected in transgenic tobacco leaves, methyl caprylate, methyl caprate, and methyl dodecanoate were newly generated, and the concentrations of methyl benzoate and methyl tetradecanoate were significantly increased, suggesting that MdAAT2 may use medium-chain fatty acyl CoA and benzoyl-CoA as acyl donors together with methanol acceptors as substrates. Surprisingly, the concentrations of linalool were significantly increased in transgenic tobacco leaves, which may mediate the repellent effect on Myzus persicae (Sulzer) aphids. Using methyl jasmonate (MeJA) and wounding treatments, we found that MdAAT2 may substitute for the partial ability of MeJA to induce the production of linalool in transgenic plants. These data suggest that MdAAT2 may be involved in the response to the MeJA signal and may play a role in the response to biotic and abiotic stress. [source] ChemInform Abstract: Convenient N-Formylation of Amines in Dimethylformamide with Methyl Benzoate under Microwave Irradiation.CHEMINFORM, Issue 40 2010Dongsik Yang Abstract Primary and secondary amines are formylated by DMF using methyl benzoate as catalyst. [source] 13C and 1H nuclear magnetic resonance of methyl-substituted acetophenones and methyl benzoates: steric hindrance and inhibited conjugationMAGNETIC RESONANCE IN CHEMISTRY, Issue 10 2004ínský Abstract The 1H and 13C NMR spectra of 14 methyl-substituted acetophenones and 14 methyl-substituted methyl benzoates were assigned and interpreted with respect to the conformation of the Car,C(O) bond. The substituent effects are proportional in the two series and can be divided into polar and steric: each has different effects on the 13C SCS of the individual atoms. In the case of C atoms C(O), C(1) and CH3(CO), the steric effects were quantitatively separated by comparing SCS in the ortho and para positions. The steric effects are proportional for the individual C atoms and also to steric effects estimated from other physical quantities. However, they do not depend simply on the angle of torsion , of the functional group as anticipated hitherto. A better description distinguishes two classes of compounds: sterically not hindered or slightly hindered planar molecules and strongly sterically hindered, markedly non-planar. In order to confirm this reasoning without empirical correlations, the J(C,C) coupling constants were measured for three acetophenone derivatives labeled with 13C in the acetyl methyl group. The constants confirm unambiguously the conformation of 2-methylacetophenone; their zero values are in accord with the conformation of 2,6-dimethylacetophenone. The zero values in the unsubstituted acetophenone are at variance with previous erroneous report but all J(C,C) values are in accord with calculations at the B3LYP/6-311++G(2d,2p)//B3LYP/6,311+G(d,p) level. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||