Oxidation by thionyl chloride

This intermediate would be further oxidized by thionyl chloride and solvolyzed by ethanol to the pyridinium chloride hydrochloride. According to this reaction route, the stoichiometric ratio of pyridine to thionyl chloride for the overall process would be about 1 1. Varying ratios of thionyl chloride have been used6-8 and varying yields of the product have been reported, ranging from 60% of crude product7 to 48% of recrystallized product.8 In one run in which the checkers used one-half the specified amount of thionyl chloride, the yield was unaffected. The submitters report yields in the range 58-62% by the procedure described here. 

One bond in substituted cubanes was cleaved oxidatively by thionyl chloride to yield polycyclic derivatives of dichlorocyclohexanes in 86-92% yield.147... 

Thion chloride can not only oxidize metal ions in complexes, it can also oxidize coordinated lig ds. Thus, the phthalocyaninatooobaltGD complex, [Pc -Co a2], is oxidized by thionyl chloride in two steps. In the first step, the metal ion is oxidized to give the oobaltOn) derivative, [Pc2-Co la2l and, in die second step, the complex, DPc CoHia2l is formed with a radical ligand. 

The existence of a substituted pyridine molecule such as III was considered as a probable intermediate for the oxidation of pyridine to l-(4-pyridyl) pyridinium ion by thionyl chloride (10). The authors believe the mechanism of the reaction with thionyl chloride to be similar to that proposed here, but further discussion of... 

Preparation of Vanadium Oxychloride by Reacting Vanadium(V) Oxide with Thionyl Chloride. Place 16 g of ammonium vanadate into a porcelain crucible. Roast the substance up to a constant mass at 500-550 °C in a crucible furnace, passing oxygen into the latter via a glass tube from a gas meter. 

Ferric oxide is not attacked by thionyl chloride, SOCl2, at the ordinary temperature. At 150° C. the following reaction readily takes place —... 

Numerous methods have been described for the preparation of niobium(V) chloride, among them the reaction of niobium(V) oxide with thionyl chloride in a sealed system. In such a procedure some niobium(V) oxide trichloride, NbOCls, is almost always formed, and it is difficult to obtain the pentachloride completely free from this impurity, even by repeated sublimation. The simple, efficient method described here consists in allowing hydrous niobium(V) oxide to react with thionyl chloride at room temperature. Almost quantitative conversion is observed, the pentachloride dissolving in the thionyl chloride, from which it may be recovered, free of oxide trichloride, by vacuum evaporation... 

In addition to the obvious preparative advantages inherent in the pentachloride preparation, e.g., the low temperature of reaction and the possibility of performing the reaction without precautions against atmospheric moisture because of the protection afforded by thionyl chloride, the product is obtained free from oxide chloride. The major losses occur during the hydrous oxide precipitation and the nitric acid washings. The latter are essential to remove adsorbed ammonium ion, since, if this is not done, the reaction products will be niobium (V) chloride, in solution in thionyl chloride, and the bright yellow insoluble ammonium hexachloroniobate(V). In fact, the high purity of these two products in instances where complete removal of ammonium ion is not achieved shows clearly that the reaction of hydrous niobium (V) oxide with thionyl chloride is virtually quantitative. 

The addition of thiobenzophenone to nitrosobenzene to give N-(diphenyl-methylene)benzenamine is said to go via a cyclic intermediate that loses sulfur monoxide to give the product. A similar mechanism is invoked in the reaction of aldehydes with 5,5 -diphenylsulfilimine to give enamines or nitriles (e.g., 587). Oxa-2,3-thiazete-2-oxides are suggested as intermediates in the dehydration of aryl amides to nitriles by thionyl chloride.The reaction of Af-sulfilamines with aldehydes, which previously were suggested to give oxa-2,3-thiazetidine-2-oxides, has been shown to yield acyclic compounds. 

Tetrahydrothiazines may be converted into dihydrothiazines by oxidation with thionyl chloride or chlorine. For example, 88 afforded 89 when... 

An efficient conversion of a hydroxy-imine into a fused oxazole ring under relatively mild conditions is effected by either silver oxide or thionyl chloride. Ekirium manganate is claimed to be more efficient than manganese dioxide in this cyclization. 

Cyclization of 2-sulfanylbenzanilide by thionyl chloride is used to synthesize 3-phenyl-1,2,3-benzodithiazi n-4(3//)-one 2-oxide.24... 

The 4,10,16-triaza-18-crown-6 macrocycle shown above was first prepared by Lehn and coworkers (Graf and Lehn, 1975 Lehn, 1985) and was an important intermediate for the synthesis of the first macrotetracyclic polyethers (Canceill et al., 1982 Kotzyba-Hibert et al., 1981 Pratt et al., 1988). The key step in this synthesis was conversion of A-tosyldiethanolamine [TsN(CH2CH20H)2] into the diacid dichloride, TsN(CH2CH20CH2C0Cl)2. As shown above, this conversion was accomplished by reaction with chlo-roacetic acid followed by oxalyl chloride (method A) (Miller et al., 1989) or by chloromethylation, sodium cyanide, hydrolysis and conversion of the diacid to the diacid dichloride (method B) (Graf and Lehn, 1981). The third hypothetical method to the diacid dichloride shown above starts with tosylamide and 5-chloro-3-oxa-l-pentanol followed by Jones oxidation and thionyl chloride (method C) (Qian et al., 1990). 

The classical permanganate oxidation of a-pinene yields cis-pinonic acid (383). Now, using dicyclohexyl-18-crown-6 ether in benzene, the yield has been raised to 90%. In the conventional oxidation, the yield of the acid (383) is very low, but in the neutral part the interesting ether (384) has been found. This is quantitatively dehydrated by thionyl chloride to (385), which has led to the synthesis of ( - )-7-epichrysanlhenol (386), the structure of which was linked to chrysanthe-none by oxidation. It has been noted that with iodosobenzene diacetate and... 

Other possibilities to obtain VPA are by hydrolysis of vinylphosphonic dichloride or from phosphorus trichloride, ethylene oxide, and thionyl chloride, following five steps. An economical method consists in the heating of 2-acet03grethylphosphonic acid diallqrl esters (allgrl = methyl, ethyl) at a temperature around 200 °C, in the presenee of an aeidie or basic catalyst when a teehnieal grade crude VPA or ester eontaining crude VPA is obtained. 

On heating in methylene chloride, the cyclopropenylium cyclopropene (633) rearranges to the spiro[2,3]hexadienylium system (634), which can be trapped as (635 R = OH or OMe) by addition of water or methanol. The alcohol (635 R = OH) is converted by thionyl chloride into the chloride (635 R = Cl) and the latter can be transformed back into the spiro-cation (634) with silver ion. Manganese dioxide oxidation of the alcohol (635 R = OH) affords the lactone (636) rather than (637). The spiro-cation (634) cannot be converted back into (633X nor does it isomerize to the Dewar-benzene cation, presumably because of the bisected conformation of the cyclopropane double bond and the allyl cation moiety. ... 

The reactivity of thioureas towards oxidants, however, has been more extensively studied. 1,3-Disubstituted thio- and seleno-ureas have been converted into the corresponding ureas by means of DMSO in the presence of an acidic catalyst. l,l-Dimethyl-3-phenylthiourea was oxidized by benzenesulphenyl chloride, thionyl chloride, sulphuryl chloride, and sulphur monochloride to the same product, (339). The oxidation of thioureas... 

Carbonyl compounds or nitriles with a-hydrogens may be oxidized at this position by thionyl chloride. This reaction appears more often as a troublesome side reaction than a useful synthetic procedure. Nitriles with one a-hydrogen produce a-cyanosulfinyl chlorides (eq 12) while those with two a-hydrogens give moderate yields of a-chloro-a-cyanosulfinyl chlorides. ... 

Sulfur dichloride is oxidized by sulfur trioxide or chlorosulfuric acid [7790-94-5] (qv) to form thionyl chloride ... 

Thallium (ITT) fluoride has been prepared by the action of fluorine or bromine trifluoride on thaUium(III) oxide at 300°C. It is stable to ca 500°C but is extremely sensitive to moisture. Thallium (ITT) chloride can be obtained readily as the tetrahydrate [13453-33-3] by passing chlorine through a boiling suspension of HCl in water. It can be dehydrated with thionyl chloride. Thallium (ITT) bromide tetrahydrate [13453-29-7] is prepared similarly, whereas the iodide prepared in this manner is thaUium(I) triiodide [13453-37-7] H" F2-... 

---