Hexane and derivs

Selkoe DJ, Luckenbill-Edds L, Shelanski ML. 1978. Effects of neurotoxic industrial solvents on cultured neuroblastoma cells Methyl n-butyl ketone, n-hexane and derivatives. J Neuropathol Exp Neurol 37 768-789. 

See l-Aceto-3,5-dinitro-triazacyclohexane under Ac etotriazacy do hexane and Derivatives N Acetyl hexohydrodi phenyl amine. See N-Cyclohexylacet anilide Acetylhexohydrotrioxlne, See Acetotriaza-cydohexane... 

A selective and sensitive spectrophotometric method for determination of atorvastatin and fluvastatin in tablets have been developed after derivatization with 9-chloromethylanthracene. Atorvastatin and fluvastatin were reacted with 9-chloromethylanthracene in hexane and then tetrabuthylammonium hydroxide for 20 at 90 °C. For spectrophotometric method the derivatives of atorvastatin and fluvastatin were measured at wavelengths, 301 and 303 nm, respectively. The developed method was applied to analyze the atorvastatin and fluvastatin contents in tablets. 

Naphthazarin (5,8-dihydroxy-1,4-naphthoquinone) [475-38-7] M 190.2, m 220-230°(dec), m 225-230°, pKEst(i) 9.5, pKEst(2) ll-l Red-brown needles with a green shine from EtOH. Also recrystd from hexane and purified by vacuum sublimation. [Huppert et al. J Phys Chem 89 5811 1985.] It is sparingly soluble in H2O but soluble in alkalis. It sublimes at 2-10mm. The diacetate forms golden yellow prisms from CHCI3, m 192-193° and the 5,8-dimethoxy derivative has m 157° (155°) (from pet ether) [Bruce and Thompson J Chem Soc 1089 7955 IR Schmand and Boldt J Am Chem Soc 97 447 1975 NMR Brockmann and Zeeck Chem Ber 101 4221 1968]. The monothiosemicarbazone has m 168°(dec) from EtOH [Gardner et al. J Am Chem Soc 74 2106 7952]. 

Acetonitrile-n-hexane partition is an effective method for oily samples, e.g. brown rice (rice bran contains oily materials) and nuts. The residue of organic layer derived from Section 2.2.3(a) is dissolved in 30 mL of n-hexane and naproanilide and its metabolite are extracted twice with 30 mL of acetonitrile. The combined acetonitrile extract is concentrated prior to further cleanup, if needed. This method can be applied to the determination of all other anilide compounds. 

HPLC ESI MS is also a useful tool in the analysis of non-anthraquinone red dyestuffs. The use of this technique allows the identification of carthamin as the main colour component of safflower.[34] Ten species of the genus Alkanna are extracted with hexane, and dissolved in water-methanol solution after evaporation. [47] Ammonium formate buffer (pH 3.0) was used as the mobile phase modifier. In the preparations, alkannin and many hydroxynaphthoquinones (alkannin derivatives) were identified by comparison of retention times, as mass spectra (in the NI mode) for all compounds consisted only of quasi-molecular peaks. 

The thermolysis of ladderanes has been studied in detail (Scheme 1). On heating, bicyclo[2.2.0]hexane and its derivatives exhibit skeletal inversion and cleavage to 1,5-hexadiene derivatives.26 The thermolysis of anti- and yyft-tricyclo[4.2.0.02,5]octanes and their derivatives gives cis,cis- and cis, trans-1,5-cyclooctadienes, cis- and trans-1,2-divinylcy clobutanes, and 4-vinylcyclohexene as ring-opening products.27-29 Furthermore, syn-tricyclo-[4.2.0.02,5]octane isomerizes to aw//-tricyclo[4.2.0.02,5]octane.29c,d The thermodynamic parameters and the reaction mechanisms for these thermal reactions have been discussed. 

As with other haloaromatic systems, Barbier reactions are also suitable for heterocyclic systems. For example, the lithio derivatives formed in situ from iodide 187 upon sonication reacted immediately with electrophiles such as benzaldehyde, hexanal and diphenyl disulfide, to give good yields of 188 <00T3709>. Similar chemistry was also successful with pyrazines, pyrimidines, and pyridazines. 

General Procedure for the Formation of Benzene Derivatives (see Eq. 2.48) At 0°C, dimethyl acetylenedicarboxylate (284 mg, 2 mmol) and CuCl (198 mg, 2 mmol) were added to a solution of zirconacyclopentadiene (1 mmol) in THF, prepared in situ according to the known procedure [12]. The reaction mixture was then allowed to warm to room temperature and was stirred for 1 h. After hydrolysis with 3 n HC1, the mixture was extracted with diethyl ether. The combined extracts were washed sequentially with water, aq. NaHC03 solution, brine, and water, and then dried over MgS04. Concentration in vacuo followed by flash-chromatography eluting with a mixture of hexane and diethyl ether (10 %) afforded benzene derivatives. 

The critical effect of intermediate-duration exposure to -hexane in humans is neurotoxicity, specifically peripheral neuropathy. No inhalation MRL was derived for this duration because the reports of neurological effects in humans were predominantly case reports with inadequate documentation of exposure levels or comparison with unexposed groups. A large database on neurological effects in rats exists for this duration however, the design of these experiments precluded documentation of clear dose-response relationships within a single study. Because of the limited database for oral exposure to -hexane and the lack of toxicokinetic data for this route, no MRL was derived for oral exposure to -hexane. 

Nylen P, Hagman M. 1994. Function of the auditory and visual systems, and of peripheral nerve, in rats after long-term combined exposure to -hexane and methylated benzene derivatives. II. Xylene. Pharmacol Toxicol 74(2) 124-9. 

The densities of the HA and the three esters were evaluated at 40°C by means of a Wesphail balance using -hexane and chloroform as reference liquids. These two liquids were chosen because of their negligible solubility in the HA and its derivatives. 

Here are the key points. First, the most abundant volatiles in tomatoes are derived from catabolism of essential fatty acids. Linoleic acid is the precursor for hexanal and linolenic acid is that for cw-3-hexenal, cH-3-hexenol, and trans-2-hexenal. All of these are important flavor elements in the tomato. A healthy diet for people requires... 

Irradiation of BeP in hexane solution did not lead to the formation of the major derivates produced on adsorbed phases. This result suggests that BeP in nonpolar solvents photodegrades through a different reaction pathway than when adsorbed on surfaces. The type of solvent may affect, on the other hand, BeP photodegradation. In acetonitrile, for example, the photodegradation rate is faster than in hexane, and dione has been detected as one of the products. 

The (R)-(+)-chiral 1,4-diol 17b was easily prepared from L-(+)-dimethyl tartrate. Dimethyl tartrate was converted to the corresponding phenylethylidene derivative by treatment with 1,1-dimethoxy-l-phenylethane and cat. p-toluenesulfonic acid in refluxing benzene, followed by conversion to the diol 17b with excess phenylmagnesium bromide. The diol was purified by column chromatography on silica gel (hexane ethyl acetate =5 1), and recrystalization from a mixture of hexane and 2-propanol. 

Recently, Nakamura and coworkers described a related reaction of the zinc enolates derived from /3-aminocrotonamides of type 395256. In the presence of a stoichiometric amount of Et2Zn, the latter underwent smooth addition to terminal alkynes upon heating in hexane and afforded the corresponding tetrasubstituted 2-alkylidene acetoacetamides 396 (after acidic hydrolysis of the imine) with high (Z)-stereoselectivity (equation 173). 

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