Oximes alcohols

Oxime carbamates have high polarity and solubility in water and are relatively chemically and thermally unstable. They are relatively stable in weakly acidic to neutral media (pH 4-6) but unstable in strongly acidic and basic media. Rapid hydrolysis occurs in strongly basic aqueous solutions (pH > 9) to form the parent oxime/alcohol and methylamine, which is enhanced at elevated temperature. Additionally, oxime carbamates are, generally, stable in most organic solvents and readily soluble in acetone, methanol, acetonitrile, and ethyl acetate, with the exception of aliphatic hydrocarbons. Furthermore, most oxime carbamates contain an active -alkyl (methyl) moiety that can be easily oxidized to form the corresponding sulfoxide or sulfone metabolites. 

Hydrogen bond types that are widely used in organic crystal engineering, primarily D-H A where D, A = O or N, will inevitably be important in inorganic systems since the same functional groups that form such hydrogen bonds, i.e. carboxyl, amide, oxime, alcohol, amine, etc., can be present as part of organic... 

The electrophilic ester carbonyl is susceptible to nucleophilic addition, the most nucleophilic site now available is the oxygen of the oxime. Alcohols and esters react to give esters, and here there is lactone (i.e. a cyclic ester) formation by standard addition-elimination mechanism at an ester. 

Blocked isocyanates permit making coatings that are stable at ambient temperature when baked, the monofunctional blocking agent is volatilized and the coreactant is cross-linked. An extensive review of blocked isocyanates, their reactions, and uses is available (127). The blocking agents most widely used are phenols, oximes, alcohols, e-caprolactam (hexahydro-2ff-azepin-2-one) [105-60-2], 3,5-dimethylpyrazole, 1,2,4-triazole, and diethyl malonate (propanedioic acid diethyl ester) [105-53-3]. A variety of catalysts are used DBTDL is most widely used but many other catalysts have also been used. Bismuth tris(2-ethyl hexanoate) has been particularly recommended (128). In electrodeposition primers, DBTDL has insufficient hydrolytic stability, and tributyltin oxide is an example of an alternate catalyst (129). Cyclic amidines, such as l,5-diazabicyclo[4.3.0]non-5-ene, are reported to be superior catalysts for use with uretdione cross-linkers in powder coatings (130). 

Usually prepared by the action of NaCN on benzaldehyde in dilute alcohol. It is oxidized by nitric acid to benzil, and reduced by sodium amalgam to hydrobenzoin PhCHOHCHOHPh by tin amalgam and hydrochloric acid to des-oxybenzoin, PhCH2COPh and by zinc amalgam to stilbene PhCH = CHPh. It gives an oxime, phenylhydrazone and ethanoyl derivative. The a-oxime is used under the name cupron for the estimation of copper and molybdenum. 

Beckmann rearrangement of cvc7ohexanone oxime. M.p. 68-70 C, b.p. I39 C/12 mm. On healing it gives polyamides. Used in the manufacture of Nylon[6]. Cyclohexanone oxime is formed from cyclohexane and niirosyl chloride. U.S. production 1978 410 000 tonnes, capryl alcohol See 2-octanol. caiH Uc acid See oclanoic acid. 

For water insoluble aldehydes or ketones, the following alternative procedure may be used. Reflux a mixture of 0-6 g. of the aldehyde or ketone, 0 5 g. of hydroxylamine hydrochloride, 5 ml. of ethanol and 0 5 ml. of pyridine on a water bath for 15-60 minutes. Remove the alcohol either by distillation (water bath) or by evaporation of the hot solution in a stream of air (water pump). Add 5 ml. of water to the cooled residue, cool in an ice bath and stir until the oxime crystallises Filter off the solid, wash it with a little water and dry. Recrystallise from alcohol (95 per cent, or more dilute), benzene, or benzene - light petroleum (b.p. 60-80°). 

By the reduction of oximes with sodium and absolute ethyl alcohol, for example ... 

Oximes (compare Section III,74,B). The following procedure has wide application. Dissolve 0-5 g. of hydroxylamine hydrochloride in 2 ml. of water, add 2 ml. of 10 per cent, sodium hydroxide solution and 0-2 g. of the aldehyde (or ketone). If the latter is insoluble, add just sufficient alcohol to the mixture to give a clear solution. Heat the mixture under reflux for 10-15 minutes, and then cool in ice. If crystals separate, filter these off, and recrystallise from alcohol, dilute alcohol, benzene or light petroleum (b.p. 60-80°). If no solid separates on cooling, dilute with 2-3 volumes of water, filter the precipitated sohd, and recrystallise. 

Beckmann rearrangement of benzophenone oxime to benz-anilide. Dissolve 2 g. of benzophenone oxime in 20 ml. of anhydrous ether in a small conical flask and add 3 g. of powdered phosphorus pentachloride (or 3 ml. of pure tbionyl chloride). Distil off the solvent and other volatile products on a water bath CAUTION ether), add 25 ml. of water, boil for several minutes and break up any lumps which may be formed. Decant the supernatant liquid, and recrystallise, in the same vessel, from boiling alcohol. The product is benzanilide, m.p. 163° confirm this by a mixed m.p. determination with an authentic specimen. 

Compounds containing one or more —OH or —SH groups, such as water, alcohols, phenols, oximes, hydrogen sulphide and thiols. 

Nylon-12. Laurolactam [947-04-6] is the usual commercial monomer for nylon-12 [24937-16-4] manufacture. Its production begins with the mixture of cyclododecanol and cyclododecanone which is formed in the production of dodecanedioic acid starting from butadiene. The mixture is then converted quantitatively to cyclododecanone via dehydrogenation of the alcohol at 230—245°C and atmospheric pressure. The conversion to the lactam by the rearrangement of the oxime is similar to that for caprolactam manufacture. There are several other, less widely used commercial routes to laurolactam (171). 

Citral readily forms acetals by acid-catalyzed addition of alcohols or by the use of trialkoxyorthoformates. Citral dimethyl acetal [7549-37-3] is stable under alkaline conditions, whereas citral is not. Neryl and geranyl nitriles can be made by oximation of citral and dehydration of the intermediate oxime. For instance, geranonitrile [31983-27-4] is made as follows ... 

Vinyl chloride reacts with sulfides, thiols, alcohols, and oximes in basic media. Reaction with hydrated sodium sulfide [1313-82-2] in a mixture of dimethyl sulfoxide [67-68-5] (DMSO) and potassium hydroxide [1310-58-3], KOH, yields divinyl sulfide [627-51-0] and sulfur-containing heterocycles (27). Various vinyl sulfides can be obtained by reacting vinyl chloride with thiols in the presence of base (28). Vinyl ethers are produced in similar fashion, from the reaction of vinyl chloride with alcohols in the presence of a strong base (29,30). A variety of pyrroles and indoles have also been prepared by reacting vinyl chloride with different ketoximes or oximes in a mixture of DMSO and KOH (31). 

Triphenylisoxazole can be synthesized by the condensation of 1,4-dilithiodeoxyben-zoin oxime with Af,fV-dimethylbenzamide (78JOC3015) and from the rearrangement of triphenylisoxazoline fV-oxide (369) in aqueous alcoholic sodium hydroxide (24JA2105). A number of other synthetic routes to triphenylisoxazole have been reported (62HC(i7)i, p. 57) but these are of relatively iftinor importance. 

H-Bonding, Strongly Associative (HBSA) Water Primary amides Secondary amides Polyacids Dicarboy lic acids Monohydro) acids Polyj)henols Oximes Hydroj laniines Amino alcohols Polyols... 

Long range functionalization of alcohols via nitrites leading to y-hydroxy oximes... 

Reductive amination ol aldehydes or ketones by cyanoborohydride (or tnacetoxyborohydride) anion Selective reduction of carbonyls to alcohol, oximes to N alkylhydroxylarmnes, enamines to amines... 

Ketones are more stable to oxidation than aldehydes and can be purified from oxidisable impurities by refluxing with potassium permanganate until the colour persists, followed by shaking with sodium carbonate (to remove acidic impurities) and distilling. Traces of water can be removed with type 4A Linde molecular sieves. Ketones which are solids can be purified by crystallisation from alcohol, toluene, or petroleum ether, and are usually sufficiently volatile for sublimation in vacuum. Ketones can be further purified via their bisulfite, semicarbazone or oxime derivatives (vide supra). The bisulfite addition compounds are formed only by aldehydes and methyl ketones but they are readily hydrolysed in dilute acid or alkali. 

The melting point of /3,/3-diphenylpropiophenone is given in the literature -d as 96°. The product melting at 91-02° was recrystallized to constant melting point from alcohol and from ligroin but the melting point remained at 92° (corr.). The oxime... 

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