2- ethyl succinate

If, however, the sodium hydroxide is removed by allowing it to react with excess of an ester of high boiling point, such as ethyl succinate or ethyl phthalate, super-dry ethyl alcohol may be obtained ... 

A good grade of absolute alcohol is required. For this purpose ordinary absolute alcohol may be dried by treating with a little sodium, adding a few cubic centimeters of ethyl succinate, and distilling directly into the reaction flask (see also Org. Syn. Coll. Vol. i, 255). 

The ethyl oxalate was redistilled, and the fraction boiling at 106-107°/25 mm. was used. The ethyl succinate was c.p. material obtained from Eimer and Amend and was used without further purification. 

Ethyl oxalylsuccinate has been prepared by the condensation of ethyl oxalate with ethyl succinate in the presence of sodium ethoxide or of potassium ethoxide. The method described above is somewhat more convenient, and has given a higher yield of a better product, than one based upon sodium ethoxide, submitted by A. E. Martell and R. M. Herbst. 

With the cxoepLion, howev V, o( trierhyl citrate, nearly all the nonvolatile esters are to a great extent, removed mechanically during the evaporation in tbe oil vapour- To delect, Cor example, glycer) acetate, ethyl oxalate., ethyl tarlrate, aod ethyl succinate, the evaporation should only be proceeded with until about 10 to 16 pet cent, of the oil is left in the dtsb, and this residee tested for Ibe varioua acids,... 

The Detection of Artificial Esters in Essential Oils.—The custom of valuing certain essential oils, such as lavender, bergamot, geranium, petit-grain, etc., by the determination of their ester-content, has led to the use of scientific adulterants in the form of artificial esters which have been deliberately employed for the purpose of misleading the analyst. Of course, the ester determination is not a true criterion of value, as most of this class of oUs owe their perfume value to various other bodies as well. The first compounds of this nature employed for adulteration were ethyl succinate and ethyl oxalate. For the detection of these in lavender oil the foUowing test was proposed by Guildemeister and Hoffman —... 

Ethyl Oxomalonate, 4,27 Ethyl Phenylacetate, 2, 27 Ethyl Propane-i, i, 2, 3-tetracar-boxylate, 4, 20, 77 Ethyl succinate, 6, 10 Ethyl sulfate, 4, 60... 

Ofloxacin 300 mg orally twice daily for 7 days, or levofloxacin 500 mg orally once daily for 7 days, or erythromycin base 500 mg orally four times daily for 7 days, or erythromycin ethyl succinate 800 mg orally four times daily for 7 days Erythromycin base 250 mg orally four times daily for 14 days, or erythromycin ethyl succinate 800 mg orally four times daily for 7 days (or 400 mg orally four times daily for 14 days... 

Succinic anhydride has been obtained by distillation of succinic acid with phosphorus pentachloride, or from benzoyl chloride and sodium succinate.1 It has been prepared from succinic acid and phosphorus oxychloride or phosphorus pentachloride 2 by distillation of succinic acid with phosphorus pent-oxide 3 from acetyl chloride and barium succinate, or from sue-cinyl chloride and sodium acetate 4 from ethyl succinate and benzoyl chloride 5 from succinic acid and acetyl chloride, or from sucdnyl chloride and oxalic acid 6 from succinic acid and suc-cinyl chloride from succinic acid and acetic anhydride 7 from succinic add and acetyl chloride 8 and from sodium succinate and acetic anhydride.9... 

Methyl hydrogen succinate has been prepared by heating succinic acid with methyl succinate,2 by treating ethyl succinate with sodium methoxide,3 and by heating succinic anhydride with methanol.4 5 ... 

Semisynthetic Derivatives. Erythromycin has been the principal subject of modification of 14-membered macrolides some of the derivatives are being commercially launched. Derivatives of erythromycin and oleandomycin include 2-U-nee ly I erythromycin (C331129NO t. 2 -O-propionylerythromycin (QoHtiNOm), erythromycin ethyl carbonate (C/0H71NO15), erytliromydn ethyl succinate (C 3H75NOi2), tn-O-acetyloleandomycin (C4iHc7NOi5), erythromycin-11,12-carbonate... 

For the removal of the last traces of water the alcohol ihay be refluxed several hours with small quantities of sodium and ethyl succinate or phthalate. (J. C. 8., 1927, 1288 Am. Soc., 1931, 1106.)... 

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