Acetal ethyl formate method

Successful results have been obtained (Renfrew and Chaney, 1946) with ethyl formate methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec.-butyl and iso-amyl acetat ethyleneglycol diacetate ethyl monochloro- and trichloro-acetates methyl, n-propyl, n-octyl and n-dodecyl propionates ethyl butyrate n-butyl and n-amyl valerates ethyl laurate ethyl lactate ethyl acetoacetate diethyl carbonate dimethyl and diethyl oxalates diethyl malonate diethyl adipate di-n-butyl tartrate ethyl phenylacetate methyl and ethyl benzoates methyl and ethyl salicylates diethyl and di-n-butyl phthalates. The method fails for vinyl acetate, ieri.-butyl acetate, n-octadecyl propionate, ethyl and >i-butyl stearate, phenyl, benzyl- and guaicol-acetate, methyl and ethyl cinnamate, diethyl sulphate and ethyl p-aminobenzoate. 

The critical temperatures and pressures have been measured for acetic anhydride and ethyl formutc The critical density is uvailabk only for ethyl formate. The method of Riedel1 was used lo estimate the critical temperatures and pressures of propionic acid and isopropyl acetate Vowlcs method was used to calculate the critical densities 1... 

Stull Mimmun/cs the data available on the vapor pressures of acetic anhydride and ethyl formate from the melting point to tile critical point, and for propionic anhydride and isopropyl acetate up to the boiling point 1 The vapor pressures ubove the boiling point were estnriuccd by a previously described method ... 

The liquid heat capacities have been determined at 20 C for acetic anhydride and propionic anhydride J The heat ca polities of ethyl formate and acetic anhydride urc presented using (lie constants to (lie equation presented by Lyman and Danner.37,3 The method uf Yuan and Sieil 0- has been used to determine the heat capacity of Isopropyl acetate. The data for propionic anhydride were extended by the equation heat capacity iime density equals a constant... 

Data arc available from O C to the critical point for ethyl formate. from tTC to 140 C for acetic anhydride.W w n and at room temperature for propionic anhydride. Sudden s method ho been used to calculate the surface tensions at other temperature. ... 

The impact of the extraction conditions using various solvents on the recoveries has never been studied in detail, and the results have never been compared. The introduction of modern extraction methods, such as microwave-assisted extraction, supercritical fluid extraction, and solid-phase extraction, probably will improve the efficiency of extraction, even in the instance of unstable pigments and pigment mixtures. The majority of TLC separations were carried out on traditional silica layers. As the chemical structures and, consequently, the retention characteristics of pigments are highly different, a wide variety of eluent systems has been employed for their separation, consisting of light petroleum, ethyl formate, ethyl acetate, benzene, toluene, chloroform, methanol, n-butanol, formic or acetic acid, and so forth. 

Co (CO) 2, and (n -C5H5)(n -Ci4Phtj)Co. 35 As a consequence, alternate methods for the preparation of functionally substituted cyclo-pentadienyl metal compounds became an important goal of our research. Sodium cyclopentadienide containing aldehyde, ketone, and ester substituents can be made by the reactions of C5H5Na with ethyl formate, methyl acetate, methyl chloroformate, and dimethyl carbonate (Scheme l),36-39... 

Suitable solvent systems for the separation of aglycones on silica layers include petroleum ether-ethyl acetate-formic acid (75 25 1) (58) and petroleum ether-ethyl formate-formic acid (75 25 5). The mobile phase in Ref. 60 offers no advantages compared with earlier systems. Finally, a method developed by Ebel and Kaal involves direct hydrolysis of the glycosides on the TLC plate (61). 

Ethoxyethylperoxyls were prepared by a variety of methods and react to give ethyl acetate, ethanol, acetaldehyde and ethyl formate. (Table V). There was no evidence for the formation of di-(1-ethoxyethyl) peroxide, a result that is not entirely incompatible with Diaper s work in view of the large difference in the size the peroxy radicals studied by the two groups of workers. The absolute yields of the products were difficult to ascertain with any degree of certainty because of secondary reactions. The high yield of ethyl formate is, however, diagnostic for the intermediacy of alkoxy radicals and indicates that at least 20 of the self-reactions of 1-ethoxyethylperoxyls occur via the radical mechanism. 

Ghlorohydrination with Nonaqueous Hypochlorous Acid. Because the presence of chloride ions has been shown to promote the formation of the dichloro by-product, it is desirable to perform the chlorohydrination in the absence of chloride ion. For this reason, methods have been reported to produce hypochlorous acid solutions free of chloride ions. A patented method (48) involves the extraction of hypochlorous acid with solvents such as methyl ethyl ketone [78-93-3J, acetonitrile, and ethyl acetate [141-78-6J. In one example hypochlorous acid was extracted from an aqueous brine with methyl ethyl ketone in a 98.9% yield based on the chlorine used. However, when propylene reacted with a 1 Af solution of hypochlorous acid in either methyl ethyl ketone or ethyl acetate, chlorohydrin yields of only 60—70% were obtained (10). 

Nonvolatile Nitrosamines In Tobacco. A method which we developed several years ago for the analysis of tobacco-specific nitrosamines (TSNA 31) involves extraction of tobacco with buffered ascorbic acid TpH 4.5) followed by partition with ethyl acetate, chromatographic clean-up on silica gel, and analysis by HPLC-TEA (Figure 9). Results obtained with this method for a large spectrum of tobacco products (Table IV), strongly support the concept that the levels of nitrate and alkaloids, and especially the methods for curing and fermentation, determine the yields of TSNA in tobacco products. Recent and as yet preliminary data from snuff analyses indicate that aerobic bacteria play a role in the formation of TSNA during air curing and fermentation. 

The formation of ethylcellulose nanoemulsions by a low-energy method for nanoparticle preparation was reported recently. The nanoemulsions were obtained in a water-polyoxyethylene 4 sorbitan monolaurate-ethylcellulose solution system by the PIC method at 25 °C [54]. The solvent chosen for the preparation of the ethylcellulose solution was ethyl acetate, which is classed as a solvent with low toxic potential (Class 3) by ICH Guidelines [78]. Oil/water (O/W) nanoemulsions were formed at oil/ surfactant (O/S) ratios between 30 70 and 70 30 and water contents above 40 wt% (Figure 6.1). Compared with other nanoemulsions prepared by the same method, the O/S ratios at which they are formed are high, that is, the amount of surfactant needed for nanoemulsion preparation is rather low [14]. For further studies, compositions with volatile organic compound (VOC) contents below 7 wt% and surfactant concentrations between 3 and 5 wt% were chosen, that is, nanoemulsions with a constant water content of 90% and O/S ratios from 50 50 to 70 30. 

---