1225-85-0Relevant academic research and scientific papers
Monitoring of phthalic acid monoesters in river water by solid-phase extraction and GC-MS determination
Suzuki,Yaguchi,Suzuki,Suga
, p. 3757 - 3763 (2001)
An analytical method for monitoring 10 phthalic acid monoesters in river water was investigated by solid-phase extraction, methylation with diazomethane, and GC-MS. Two cartridge-type solid phases packed with octadesyl-coated silica (C18) and styrenedivinyl polymer (PS-2) and one disk-type solid phase made from octadesyl-coated styrene-divinylbenzene polymer (SDB-XD) were investigated in solid-phase extraction. PS-2 gave the highest recoveries of the three solid phases, and recoveries of more than 80% of the monoesters in filtered water samples were obtained at pH 2 to 3 with PS-2 at the spiked level of 0.1 μg L-1, except for monomethyl-phthalate (MMP), in which more than 72% of the monoesters were recovered. For the monoesters in the suspended solids (SS), an acidic methanol extract of SS was added to purified water acidified to pH 2, and the monoesters were extracted with PS-2. The recoveries of the monoesters in SS were more than 80%, but the recoveries of MMP were more than 57%. The method detection limit (MDL) of each phthalic acid monoester in 500 mL of water sample and in 2 mg of dry weight of SS ranged from 0.010 to 0.030 μg L-1 and from 1 to 11 μg g-1 respectively. Monitoring of phthalic acid monoesters in the Tama River in Tokyo was conducted every month from March 1999 to February 2000 using the present method. MMP, mono-n-butyl-phthalate (MBP), and mono-(2-ethylhexyl)-phthalate (MEHP) were detected at concentrations of 0.030-0.0340, 0.010-0.480, and 0.010-1.30 μg L-1. respectively, in the filtered water samples but were not detected in SS. Dimethyl-phthalate (DMP), di-n-butyl-phthalate (DBP), and di-(2-ethylhexyl)-phthalate (DEHP) were detected in the river water at concentrations of 0.010-0.092, 0.008-0.540, and 0.013-3.60 μg L-1, respectively. Diethyl-, di-iso-butyl-, and benzylbutyl-phthalates were also detected at concentrations of nanograms per liter, whereas the corresponding monoesters did not appear. The concentrations of MBP and MEHP in the river water were slightly lower than those of the corresponding diesters at the majority of sampling sites and sampling times.
Benzyl Methyl (S)-2-(p-Tolylsulfinyl)maleate, an Efficient Dienophile in Asymmetric Diels-Alder Reactions
Alonso, Ines,Carretero, Juan C.,Ruano, Jose L. Garcia
, p. 1499 - 1508 (2007/10/02)
The enantiomerically pure dienophile 3 was readily prepared in a three-step sequence from benzyl acetate and (-)-(S)-menthyl p-toluenesulfinate (46percent overall yield).This vinyl sulfoxide reacted in high
Hard Acid and Soft Nucleophile Systems. 3.1 Dealkylation of Esters with Aluminum Halide-Thiol and Aluminum Halide-Sulfide Systems
Node, Manabu,Nishide, Kiyoharu,Sai, Midori,Fuji, Kaoru,Fujita, Eiichi
, p. 1991 - 1993 (2007/10/02)
Benzyl and methyl esters of aliphatic and aromatic carboxylic acids have been easily cleaved on treatment with aluminum halide and ethanethiol to give parent carboxylic acids in quantitative yields.A new combination of aluminum halide with dialkyl sulfide has been found to make up a powerful deesterification reagent system useful for general esters.
