Dimethyl oxime

To be consistent, the same conclusion should be drawn for the dimethyl-oxime complexes. The difficulty here is to answer the question as to why other flat, uncharged, molecules do not stack in a similar fashion. It is believed that in fact they would do so were it not for factors such as mutual repulsion of u-electrons, as in condensed hydrocarbons (214). An examination of the bond lengths shown in Fig. 10 indicates that in the dimethyl-glyoxime complexes the ir-bonding is not nearly so extensive as commonly imagined. Similarly, it is known that aromatic donor-acceptor complexes, e.g, quinhydrone, stack in a fashion very similar to the dimethylglyoximc complexes (166a), and also show abnormal dichroism (182). 

Acetaldehyde can be isolated and identified by the characteristic melting points of the crystalline compounds formed with hydrazines, semicarbazides, etc these derivatives of aldehydes can be separated by paper and column chromatography (104,113). Acetaldehyde has been separated quantitatively from other carbonyl compounds on an ion-exchange resin in the bisulfite form the aldehyde is then eluted from the column with a solution of sodium chloride (114). In larger quantities, acetaldehyde may be isolated by passing the vapor into ether, then saturating with dry ammonia acetaldehyde—ammonia crystallizes from the solution. Reactions with bisulfite, hydrazines, oximes, semicarb azides, and 5,5-dimethyl-1,3-cyclohexanedione [126-81 -8] (dimedone) have also been used to isolate acetaldehyde from various solutions. 

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). 

Dimethyl ketals and enol ethers are stable to the conditions of oxime formation (hydroxylamine acetate or hydroxylamine hydrochloride-pyridine). Thioketals and hemithioketals are cleaved to the parent ketones by cadmium carbonate and mercuric chloride. Desulfurization of thioketals with Raney nickel leads to the corresponding methylene compounds, while thioenol ethers give the corresponding olefin. In contrast, desulfurization of hemithioketals regenerates the parent ketone. ... 

Because of the difficulties encountered in preparing starting materials, further data on the synthesis of these compounds are rare. Exceptionally, 3,4-dimethyl-furazan [630S(1V)342] and 3,4-dimethylfuroxan (1890CB3490, 80URP721430) were synthesized in a straightforward manner from commercially available dimethylgly oxime. 

Trimethylacetic acid may be made by the hydrolysis of tert-butyl cyanide with weak hydrochloric acid at ioo0.1 It is also obtained by oxidation of trimethylpyroracemic acid with silver oxide or potassium dichromate and sulfuric acid,2 by oxidation of tertf-butylethylene with permanganate solution,3 or by oxidation of dimethyl 2,2-propanol with chromic acid.4 Schroeter reports the formation of trimethylacetic acid by rearrangement of the oxime of trimethylacetophenone to give the anilide of trimethylacetic acid, which can be hydrolyzed to give the acid.5... 

Dibenz[c 1c ]azepine (32 a) is obtained by acid-mediated cyclization of 2 -(aminomethyl)bi-phenyl-2-carbaldehyde (31 a), which is generated in situ by reduction of the oxime acetal 30a.85 The acetyl 30 a and benzoyl 30c oximes behave similarly and give the dimethyl and diphenyl derivative 32 b and 32 c, respectively. 

Pentan-2,4-dion-bis-oxim wird an Blei/30%iger Schwefelsaure zu 3,5-Dimethyl-pyra-zolidin (40% d.Th.) cyclisiert4 ... 

Dihydroxy- -oxim 699 4,4 -Dimethoxy- -O-methyl-oxim 377 4-(2,3-Dimethyl-butyl-(2)]- 565 2,2 -Dinitro- 474, 558 4,4 -Diphenyl- 542 2 -Fluor-4-chlor- 288... 

Dimethyl dioxirane in wet acetone oxidizes isocyanates to nitro compounds (RNCO —> RN02). Oximes can be oxidized to nitro compounds with peroxytri-fluoroacetic acid, or Oxone ," sodiumperborate," among other ways. " Primary and secondary alkyl azides have been converted to nitro compounds by treatment with PhjP followed by ozone. Aromatic nitroso compounds are easily oxidized to nitro compounds by many oxidizing agents. ... 

In contrast with the Schiff base salen, salicylaldehyde oxime (79) (salox) complexes of Co have received comparatively little attention, but a series of bis-bidentate divalent complexes of the form iraiis-Co(sa 1 ox)2( D M SO)2 have been reported.343 The heterocyclic bidentate oxime violurate (lH,3H-pyrimidine-2,4,5,6-tetrone 5-oximate, Hvi) (80) and its /V-methyl (mvi) and /V,/V -dimethyl (dmvi) derivatives form high-spin divalent [Co(vi)]+ and Co(vi)2 complexes, whereas [Co(vi)3] is low spin.344 The mixed-ligand Co(dmvi)2(phen) complex is also low spin. The crystal structure of m-Co(pxo)2Br2 (pxo = 2-acetylpyridine-l-oxide oxime) is isostructural with the Ni11 relative.345 The dichloro complex also adopts a cis configuration. The tridentate dioximes 2,6-diformyl-4-methylphenol dioxime and 2,6-diacetyl-4-methylphenol dioxime (Hdampo) form binuclear complexes of the type (81a) and (81b) respectively.346 Cobalt oxide nanoparticles were prepared by... 

Besides the use of porphyrins as azomethinic ylide derivatives, the porphyrin macrocycle can also be used to generate porphyrinic nitrile oxides 55 (Scheme 17) <04RCB(E)2192>. Thus, the treatment of oxime 54 with /V-bromosuccinimide in the presence of triethylamine, led to the formation of nitrile oxide 55, which was trapped in 1,3-DC reactions with dimethyl maleate and 2,5-norbomadiene to afford 56 and 57, respectively. In the reaction with 2,5-norbomadiene, if an excess of 55 was used, then the corresponding bis-adduct was obtained in good yield. 

On treatment with dimethyl sulfoxide-acetic anhydride followed by sequential oximation, reduction, detritylation, and acid hydrolysis, a tetra-(6-0-trityl)-cyclohexaamylose was reported to afford 2-amino-2-deoxy-D-glucose, in addition to D-glucose, indicating459 that... 

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