Monoethyl phthalate

Biological. A proposed microbial degradation mechanism is as follows 4-hydroxy-3-methylbenzyl alcohol to 4-hydroxy-3-methylbenzaldehyde to 3-methyl-4-hydroxybenzoic acid to 4-hydroxyisophthalic acid to protocatechuic acid to p ketoadipic acid (Chapman, 1972). In anaerobic sludge, diethyl phthalate degraded as follows monoethyl phthalate to phthalic acid to protocatechuic acid followed by ring cleavage and mineralization (Shelton et al, 1984). 

Yim et al. (2002) studied the sonlytic degradation of diethyl phtahalate in aqueous solution. Degradation followed pseudo-first-order kinetics. Monoethyl phthalate, a hydrolysis product of diethyl phthalate, was approximately 3.3 times higher at pH 12 than at pH 7. The investigators concluded that the reaction was affected by pH of the solution. In the presence of ultrasound, the OH radical reaction, thermal reaction, and hydrolysis were all involved during the reaction. 

Monochlorobiphenyls, see PCB-1232, PCB-1260 Monochlorodibenzofuran, see PCB-1248 Monochlorovinyl acids, see Permethrin anfi-Monodechlorodieldrin, see Dieldrin sjn Monodechlorodieldrin, see Dieldrin Monoethyl phosphate, see Sulfotepp Monoethyl phthalate, see Diethyl phthalate Monohydroxychlorobiphenyl, see... 

Studies on health effects of PAEs in humans have remained controversial due to limitations of the study design. Some findings in human populations are consistent with animal data, suggesting that PAEs and their metabolites produce toxic effects in the reproductive system. Some studies associate monoesters PAEs with semen parameters, sperm DNA damage, and hormones in human population, but none of them are statistically significant. Urinary monomethyl phthalate (MMP), monobenzyl phthalate (MBzP), mono- -butyl phthalate (MBP), MEHP, and monoethyl phthalate (MEP) were associated with poor sperm morphology and vigor, and with low sperm concentration, motility, and linearity [31-35]. However, it is not yet possible to conclude whether phthalate exposure is harmful for human reproduction. 

Limited information was located regarding possible interactions of DEHP with other chemicals in humans. Urinary measurements of the monoester metabolites of seven common phthalates in 289 adults from the U.S. population, determined using the selective and sensitive analytical approach discussed in Section 3.8.1 (Biomarkers Used to Identify or Quantify Exposure to DEHP), showed detectable levels of monoethyl phthalate (95th percentile concentration, 3,750 ppb), monobutyl phthalate (294 ppb), monobenzyl phthalate (137 ppb), 2-ethylhexyl phthalate (21.5 ppb), cyclohexyl phthalate (8.6 ppb), isononyl phthalate (7.3 ppb), and octyl phthalate (2.3 ppb), reflecting exposure to DEHP, dibutyl phthalate, benzyl butyl phthalate, di-(2-ethylhexyl) phthalate, dicyclohexyl phthalate, di-isononyl phthalate, and dioctyl phthalate, respectively (Blount et al. 2000a). Considering evidence such as this which indicates that co-exposure to multiple phthalates can occur, as well as the likelihood that many of these compounds exert effects via a common mechanism of action, there is a potential for interactions between DEHP and other phthalate esters. 

Recently, monoethyl phthalate (79) has been described as a reagent for the mild and selective conversion of primary amines into their corresponding phthalimides. The procedure is based on the PyBOP-promoted reaction of the anoine with monoethyl phthalate (79) yielding an intermediate phthalamic ester that cyclizes to give the desired phthalimide (Scheme 40).t ... 

Presumably for similar reasons, cathodic reduction of diethyl terephthalate and diethyl furan- and thiophene-2,5-dicarboxylate [51-53] in a buffered ethanolic solution of pH 4.2 affords the aldehyde ester under controlled potential electrolysis (CPE) conditions (in the interval between —1.50 and —1.65 V). Diethyloxalate [77] is reduced at a mercury cathode in acidic medium to give the ethyl hemiacetal of ethyl glyoxylate (38-50% yield). In contrast, diethyl and monoethyl phthalate gave phthalide under similar conditions [21,78]. 

Controlled potential electrolyses of phthalic and pyromellitic anhydrides at the potential of the first wave gave highly colored, oxygen-sensitive solutions, which later were shown to give well-resolved esr spectra of the corresponding radical ions [55]. Phthalic anhydride has been reduced to phthalide on a preparative scale [109], but the reaction conditions employed (ethanol-water-ammonium carbonate) indicate that monoethyl phthalate must have been the actual substrate. An interesting reduction of 3,6-diphenylphthalic anhydride in the presence of trimethylsilyl chloride gives two types of dimeric species [110] ... 

Table 9.2. NIST match results for Unknown 1 (rowl), phthalic anhydride (2), phthalic acid (3), phtha-lamic acid (4) and monoethyl phthalate (5).

Butyl alcohol, ethylene glycol monoethyl ether, cyclohexanol, benzyl alcohol, diethylene glycol monobutyl ether, and dibutyl phthalate... 

Ester Content (as Ethyl Acetate) — min 85 0 max 88.0%. It shall be detd in accordance with ASTM D1617-69, described in Annual Book of ASTM Standards, Part 20(1972), 736-39 Note 1 The method described in ASTM D1617— 69 applies not only to EtAcet, but also to other esters, such as N-butyl acetate, isopropyl acetate, acetate ester of ethylene glycol monoethyl ether, sec-butyl acetate, amyl acetate, dibutyl phthalate and iso butyl acetate... 

Utilized as the deprotection method of allyl carboxylate. For example, under similar conditions, allyl ethyl phthalate is converted into phthalic acid monoethyl ester in 87% yield. 

Dibutyl Phthalate, NF Dibutyl Sebacate, NF Dichlorodifluoro-methane, NF Diethylene Glycol Monoethyl Ether, NF... 

Ethylene Glycol Monoethyl Ether Acetate 117-84-0 Dioctyl Phthalate... 

Acetone/methanol Acetone/n-hexane Benzene/isopropyl alcohol Carbon tetrachloride/methanol Acetone, heptane, toluene Butanone - methanol mixtures Xylene/ethylene glycol monoethyl ether Xylene/methanol Tetrahydrofiuan, toluene, chlorobenzene Chloronaphthalene 1 -Chloronaphthalene/20% dimethyl phthalate... 

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