Acetic acetonitrile

A liquid chromatography-mass spectrometry (LC-MS) method that can quantitatively analyze urinar y normal and modified nucleosides in less than 30 min with a good resolution and sufficient sensitivity has been developed. Nineteen kinds of normal and modified nucleosides were determined in urine samples from 10 healthy persons and 18 breast cancer patients. Compounds were separ ated on a reverse phase Kromasil C18 column (2.1 mm I.D.) by isocratic elution mode using 20 mg/1 ammonium acetate - acetonitrile (97 3 % v/v) at 200 p.l/min. A higher sensitivity was obtained in positive atmospheric pressure chemical ionization mode APCI(-i-). 

Acetic acid with chloroform, ethanol, ethyl acetate, acetonitrile, petroleum ether, or water. 

It is poorly soluble in acetone, 2-butanone, ethyl acetate, acetonitrile, and DMF, and insoluble in alcohols, petroleum ether, and diethyl ether. The partition coefficients of a number of solutes between PCL and water have been measured and correlated with octanol-water partition coefficients (Fig. 9) (58,59). The linear correlation (Eq. 2) when combined with the water solubility of the solutes serves as a method of estimating the solubility of drugs in PCL from first principles. ... 

Residual dinitroaniline herbicides are generally extracted from 10-25 g of air-dried soil samples using organic solvents such as ethyl acetate, acetonitrile, methylene chloride and acetone by sonication, mechanical shaking or Soxhlet extraction. If necessary, the extract is then cleaned by a Florisil column or SPE. The extract is allowed to evaporate completely to dryness and the residue is dissolved in an appropriate volume of the solvent for GC or HPLC analysis. 

Extraction efficiency. The efficiency of extractions of imidacloprid from vegetables and crops decreases in the order acetonitrile > acetone > ethyl acetate. Acetonitrile is not a suitable extraction solvent because of the large number of co-eluting peaks on the chromatograms on HPLC at 210 or 270 nm. ... 

In water (pH 7), 6mgL i (20°C). Low solubility in hexane, n-octanol moderate solubility in methanol, toluene, acetone high solubility in ethyl acetate, acetonitrile, dichloromethane Stable to aqueous hydrolysis... 

Ruthenium tetroxide can also be used in the oxidation of alkenes. Conditions that are selective for formation of ketols have been developed.36 Use of 1 mol % of RuC13 and five equivalents of KHS05 (Oxone ) in an ethyl acetate-acetonitrile-water mixture gives mainly hydroxymethyl ketones from terminal alkenes. 

Figure 3 A two-component (toluene/2,4-dichlorophenol) separation. Chromatographic conditions — column 30 cm x 3.9 mm pBondapak C18 (10-pm particle size) mobile phase 0.1 M ammonium acetate acetonitrile (50 50) flow rate 1.0 ml/min column temperature ambient detector wavelength 254 nm.

The chemiluminescence reaction of esters of oxalic acid can proceed within a wider pH range than for luminol. However, the most efficient oxalate derivatives are only soluble in organic solvents such as ethyl acetate, acetonitrile, dioxane or dimethoxyethane and dissolution problems of these solvents in aqueous media are encountered. This can limit the use of this chemiluminescence reaction for a direct coupling to an H202-generating enzymatic reaction. 

Water and waste water Phenols separated on a Nova-Pak Phenyl column eluted with ammonium acetate acetonitrile LC-ED 0.5 mg/L 91-100% Paterson et al. 1996... 

Figure 4.7 Effect of high organic modifier concentration on peptide retention. Data obtained using an octadecyl column and 20 mM ammonium acetate acetonitrile mobile phases. (Reproduced from C.T. Wehr and L. Correia, LC at Work LC-121, Varian. With permission from Varian Associates.)...

N-NeoDentyl)-4-DihexylaminoDvrldinium Bromide (3h) The neopentyl salt was prepared in a similar manner from neopentyl mesylate, but reaction was carried out neat at 130 for 72 hr. Higher temperatures cannot be used, due to decomposition of neopentyl mesylate. The crude product was dissolved in water, basifled to neutralize any pyridinium salt, and was washed with petroleum ether to remove amine and unreacted neopentyl mesylate. The aqueous phase was acidified with HBr, and extracted with methylene chloride, to afford crude salt. Recrystallization from 20 1 ethyl acetate/acetonitrile affords the product (mp = 169-170 ). 

The efficient At-nitration of secondary amines has been achieved by transfer nitration with 4-chloro-5-methoxy-2-nitropyridazin-3-one, a reagent prepared from the nitration of the parent 4-chloro-5-methoxypyridazin-3-one with copper nitrate trihydrate in acetic anhydride. Reactions have been conducted in methylene chloride, ethyl acetate, acetonitrile and diethyl ether where yields of secondary nitramine are generally high. Homopiperazine is selectively nitrated to At-nitrohomopiperazine or At, At -dinitrohomopiperazine depending on the reaction stoichiometry. At-Nitration of primary amines or aromatic secondary amines is not achievable with this reagent. 

System (5) has been reported for the determination of C21-hydroxy corticosteroids in human urine, and uses prednisone as the internal standard [153]. The column (25 cm x 4.6 mm) was packed with TSK gel ODS-120 T (5 pm). The mobile phase consisted of a stepwise gradient elution at 1 mL/min with methanol-IM ammonium acetate-acetonitrile... 

Copper(II) acetate 1-hydrate (98%) (204 mg, 1 mmol) Ethyl acetate Acetonitrile (5 mL)... 

The oxidation of propylene can also be carried out in other solvents, such as methyl acetate, acetonitrile, or (erf-butyl alcohol, but the rates are lower than the rate in a methanol-water mixture. The reaction in tert-butyl alcohol is further complicated by the fact that, in the presence of TS-1, the alcohol and H202 react to give TBHP (Maspero et al., 1989). 

FIGURE 10. Relative quantum yields for exciplex fluorescence (filled symbols) and addition product formation (open symbols) versus solvent dielectric constant for trans-stilbene with di isopropyl methyl amine (0)> ethyldiisopropylamine (A), and triethylamine ( ) in hexane-ethyl acetate and ethyl acetate-acetonitrile mixed solvents. From ref. (114) with permission of the American Chemical Society. 

A polar solvent, such as ethyl acetate, acetonitrile (MeCN), methanol (MeOH) or 2,2,2-trifluoroethanol (TFE) should be employed. 

Additions of crotyl tributyltin to aldehydes in the presence of 1 equiv. of InCls lead to mixtures of diastereomeric adducts favoring the anti isomer (Eq. 53) [73]. The reaction is most selective in donor solvents such as ethyl acetate, acetonitrile, or acetone. Premixing the staimane and InCls in the absence of aldehyde causes an immediate precipitate to form. Subsequent addition of the aldehyde results in slow formation of prodnct which is isolated in low yield. 

Dichloromethane Ethyl Acetate Acetonitrile M-ethanoJ Methyl-t-butyl Ether Chlortrform Dioxan... 

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