Potassium ethyl hydroxybenzoate

Synonyms ethyl 4-hydroxybenzoate potassium salt potassium ethyl hydroxybenzoate. 

Dichlorophenol Ethyl />-hydroxybenzoate with, e.g., S02C12 (2.2 moles) in 1.5 h on the water-bath affords a yield of about 85 % of ethyl 3,5-dichloro-4-hydroxybenzoate, which is hydrolysed by methanolic potassium hydroxide to 3,5-dichloro-4-hydroxybenzoic acid. This acid (1.2 moles) in dimethylaniline (575 g) is heated gradually to 190-200° and kept at this temperature until evolution of C02 ceases (about 2 h), giving 80-90% of 2,6-dichloro-phenol. For details see Organic Syntheses 451... 

This with potassium hydroxide in methanol forms de-OiV-dimethylarmepavine, m.p. 86-7°, (B. HCl, m.p. 229-30°) of which the methiodide, m.p. 233-4°, on treatment with alkali decomposes into trimetHylamine and a -p-anisyl-/3-(3 4-dimethoxy- 6 - vinylphenyl) -ethylene, m.p. 79°. The latter is oxidised by permanganate in acetone to anisic and m-hemipinic acids. With ethyl sulphate and alkali, armepavine gives 0-ethylarmepavine, an oil, which permanganate oxidises to p-ethoxybenzoic acid. Armepavine is similarly oxidised to p-hydroxybenzoic acid and l-keto-6 7-dimethoxy-2-methyl-1 2 3 4-tetiahydrowoquinoline and is therefore 6 7-dimethoxy-l-p-hydroxybenzyI-2-methyI-l 2 3 4-tetrahydrowoquinoline, i.e., it is laudanosine (p. 187) with MeO. at C replaced by H and MeO at C changed to HO. ... 

Rump [17] has described a cellulose thin layer method for the detection of phenolic acids such as iw-hydroxybenzoic acid, iw-hydroxyphenylacetic acid and m-hydroxyphenylpropionic acid, in water samples suspected to be contaminated with liquid manure. The phenolic acid is extracted with ethyl acetate from a volume of acidified sample equalling lmg of oxygen consumed (measured with potassium permanganate). The ethyl acetate is evaporated and the residue dissolved in ethanol. After spotting of a lpm aliquot on a cellulose plate the chromatogram is developed by capillary ascent with the solvent n-propanol-w-butanol-25% NH3-water (4 4 1 1 by vol). The solvent front is allowed to advance 10cm. The air-dried plate is sprayed with a diazotised p-nitroanilinc reagent to make the phenolic acids visible. 

Procedure (See Chromatography, Appendix IIA.) Use a high-performance liquid chromatograph capable of separating acesulfame potassium and 4-hydroxybenzoic acid ethyl ester with a resolution of 2. Use a chromatograph equipped with a UV or diode array (227 nm) detector and a 25-cm x 4.6-mm (id) stainless steel column, or equivalent, packed with 3 to 5 p,m of reversed phase C18 silica gel, or equivalent. The elution is isocratic. Use a 40 60 (v/v) solution of acetoni-trile 0.01 MlL tetrabutyl ammonium hydrogen sulfate (TBAHS) in water as the mobile phase, with a flow rate of about 1 mL/min. 

To a three-necked round-bottomed flask (1 L) equipped with a reflux condenser, thermometer, a dropping funnel (250 mL), and a magnetic stirrer bar, add dimethylformamide (300 mL) and anhydrous potassium carbonate (69.1 g, 0.5 mol). Using a powder funnel, add methyl p-hydroxybenzoate (60 g, 0.40 mol) together with the potassium iodide. Heat the solution to 90°C and add 6-chlorohexyl ethanoate (97.4 g, 0.54 mol) drop-wise over several hours. Stir the solution for a total of 24 h whereupon TLC (silica gel, 3 2 petroleum ether ethyl acetate) should indicate the complete conversion of starting material. 

The present procedure affords 4-hydroxy[l-13C]benzoic acid from ethyl [2-13C]acetate in three steps with 72% overall yield. It is based on an observation of Woodward17 that ethyl 4-hydroxybenzoate is formed by base-catalyzed condensation of 4H-pyran-4-one with diethyl malonate. The submitters studied several solvent-base combinations for this reaction and found that tert-butyl alcohol/potassium tert-butoxide gave the highest yields. When a stoichiometric amount of the base is used, an excess of 4H-pyran-4-one has to be used.4 ) This can be avoided by the use of substoichio-metric amounts as given in the procedure. 

Ethyl hydrosulfide. See Ethyl mercaptan Ethyl hydroxide. See Alcohol Ethyl 2-hydroxybenzoate. See Ethyl salicylate Ethyl 4-hydroxybenzoate. See Ethylparaben Ethyl-o-hydroxybenzoate. See Ethyl salicylate Ethyl p-hydroxybenzoate. See Ethylparaben Ethyl-4-hydroxybenzoate potassium salt. See Potassium ethylparaben Ethyl 3-hydroxybutanoate. See Ethyl 3-hydroxybutyrate Ethyl 3-hydroxybutyrate CAS 5405-41-4 EINECS/ELINCS 226-456-2 FEMA 3428... 

Potassium 2-ethylhexanoate CAS 3164-85-0 Uses Catalyst for PU Potassium ethylparaben CAS 36457-19-9 EINECS/ELINCS 253-048-1 Synonyms Ethyl-4-hydroxybenzoate potassium salt Ethylparaben, potassium salt Definition Potassium salt of ethylparaben Empirical C9H10O3 K... 

Phenolic acids. Table 11 lists the Rf values for a number of phenolic acids and certain of their relatives on silica gel, silanized silica gel, cellulose, and polyamide layers. Silica gel (Silica Rapid Platten Woelm F-254) was used with solvents I [dichloromethane-toluene-formic acid (50 40 10)] and II [dichloromethane-acetic acid-water (100 50 50, lower phase)], followed by UV examination of the plates and subsequent spraying with 1 % methanolic ferric chloride. HPTLC precoated plates with silica gel 60 F-254, RP-8, and Wang polyamide were used with solvents 111 [benzene-ethyl acetate-formic acid (40 10 5)], IV [ethanol-water (55 45)], and IX [benzene-ethyl methyl ketone-methanol (60 26 14)], respectively. The upper part of Table 11 lists the Revalues of hydroxybenzoic acids and the lower part those for hydroxycinnamic acids. For columns V, VI, VII, and VIII, the solvents used were 2% formic acid (V), 20% potassium chloride solution (VI), isopropanol- ammonium hydroxide-water (8 1 1) (VII), and 10% acetic acid (VIII). For each layer the relative trends of the Revalues follow the polarity of the compounds listed. Table 12 gives the Revalues for certain phenolic acids on silver oxide-impregnated silica gel G by two-dimensional development on cellulose (107). 

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