Pyridine acetic add

Furthermore, it is seen that a hydroxyl group in the molecule does not necessarily reduce the Rf value as the chromatographic behavior of serine with respect to glycine on both layers of silica gel and cellulose shows (see Table 1). Some of the numerous eluents that have been used for the separation of amino adds on silica gel are acetone-water-acetic acid-formic acid (50 15 12 3), ethylacetate-pyridine-acetic acid-water (30 20 6 11), 96% ethanol-water-diethylamine (70 29 1), chloroform-formic acid (20 1), chloroform-methanol (9 1), isopropanol-5 % ammonia (7 3), and phenol-0.06M borate buffer pH 9.30 (9 1). On cellulose plates, ethylacetate-pyridine-acetic add-water (5 5 1 3), n-bu-tanol-acetic acid-water (4 1 1 and 10 3 9), n-butanol-acetone-ammonia-water (20 20 4 1), collidine-n-bu-tanol-acetone-water (2 10 10 5), phenol-methanol-water (7 10 3), ethanol-acetic acid-water (2 1 2), and cyclohexanol-acetone-diethylamine-water... 

A recent study has confirmed that the Fenton process [Eq. (4-18)] occurs in pyridine/acetic add (2 1 molar ratio) when bis(picolinato)iron(II) [Fe (PA)2l and hydrogen peroxide are combined in 1 1 molar ratio (the rate constant for the Fe RPA)2/HOOH reaction is JxlO M- s-l). In the presence of hydrocarbon substrates (RH) the HO- flux produces carbon radicals (R-), which can be trapped by PhSeSePh to give RSePh. This chemistry, which is outlined in Scheme 4-1 for cyclohexane (C-C6H12), represents a reasonable model for HO- radical generation within biomembranes. 

Several methyl esters were synthesized by the treatment of pyridine acetic adds with diazomethane. A variety of C-21 steroidal alco-hols " and the following alcohols have been employed in esterification reactions with pyridine side-chain acids. ... 

Combining the nucleophilicity of the indole 3-position just illustrated and the well-known tendency of C-2 and C-4 vinyl pyridines to add nucleophiles, a convenient synthesis of the tranquilizer benzindopyrine (19) was devised.6 Reaction of N-benzylindole (17) with 4-vinylpyridine (18) in acetic acid produced 19 directly. 

Nitroglycerine is readily dissolved in most organic solvents and itself behaves as a good solvent. Thus, it is completely miscible in all proportions at room temperature with the following liquids methyl alcohol, ethyl acetate, anhydrous acetic add, benzene, toluene, xylenes, phenol, nitrobenzene, nitrotoluenes, pyridine, chloroform, dichloroethane, dichloroethylene, and the like. 

Another approach implies the application of glacial acetic add as a solvent [190,984], Bi(OAc)3 was mixed and stirred with pyridine. Separately, Sr(OAc)2 and Ta(OEt)5 were mixed and dissolved in glatial acetic add, then Bi-contain-... 

Toluene-pyridine—2-chloroethanol-0.8 N ammonia solution Toluene-pyridine - 2-chloroethanol- 25% ammonia Chloroform-benzyl alcbhol-glacial acetic acid Chloroform-rerr.-pentanol-glacial acetic acid Benzene-pyridine-glacial acetic add Chloroform-methanol-gladal acetic acid Chloroform-methanol-glacial acetic add 1 3 6 6 50 15 35 7 70 30 3 70 30 3 40 10 1 95 5 1 14 6 1 17,19,20... 

After about the first 6-8 hours an additional 30 ml of 70% ethyl alcohol may be added. Remove about 50% of the solvent by distillation in vacuo. Add a small amount of ice water and acidify with glacial acetic acid. Extract with chloroform (6-8 times), since the product precipitates from the acetic acid solution as a thick emulsion which cannot be filtered. Concentrate the chloroform extracts to a small volume and precipitate the product with hexane to give crude 8-chloro-6,ll-dihydro-ll-(4-piperidylidene)-5H-benzo[5,6]cyclohepta[l,2-b]pyridine acetic acid salt, m.p. 197-200°C. Recrystallize from benzene-hexane to obtain the product, m.p. 199-200°C. Yield 4.0-4.5 g. 

The 2-allylphenols in the presence of add catalysts such as pyridine hydrochloride, -66 hydrobromic add-acetic add, or formic acid86 form 2-methyldihydrobenzofurans (coumarans) such as LXYI. In the pres-... 

Procedure Pipet 1-mL portions of the Standard Solution and of the Assay Preparation into separate 100-mL, round-bottom boiling flasks. Add 1.0 mL of Internal Standard Solution to each flask, and evaporate each mixture to dryness on a water bath at 60° with the aid of a rotary evaporator. Dissolve each dry residue in 1 mL of pyridine, and add 1 mL of acetic anhydride to each flask. Boil each solution under reflux for 1 h to complete the acetylation. Separately inject l- xL portions of the derivatized solutions from the Assay Preparation and the Standard Solution into the gas chromatograph and measure the peak responses. Calculate the percent of Xylitol, on the as-is basis, by the formula... 

Unless otherwise directed, accurately weigh the appropriate amount of the sample indicated in the table below, transfer it into a 250-mL glass-stoppered Erlenmeyer flask, and add 5.0 mL of pyridine-acetic anhydride reagent (mix 3 volumes of freshly distilled pyridine with 1 volume of freshly distilled acetic anhydride). 

Predict the structure of the product formed in the reaction of the organic base pyridine with the organic acid acetic add, and use curved arrows to indicate the direction of electron flow. 

Storage Substances The reagent should always be freshly made up. Pyrocatechol violet Mobile phase Methyl isobutyl ketone — pyridine — glacial acetic add (97.5 + 1.5 + 1). 

Pale yellow needles from chloroform, mp 268-27CP pele yellow plates from glacial acetic acid, mp 250-257. [ ]S — 3 — +34 (c = 1.11 in pyridine), uv max (glacial acetic add) 335 nm (log t 4.57). One part sol in 1000 parts boiling chloroform in 800-1000 parts boiling glacial acetic acid. 

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