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Thionyl chloride adducts

A number of processes have been devised for purifying thionyl chloride. A recommended laboratory method involves distillation from quinoline and boiled linseed oil. Commercial processes involve adding various high boiling olefins such as styrene (qv) to react with the sulfur chlorides to form adducts that remain in the distillation residue when the thionyl chloride is redistilled (179). Alternatively, sulfur can be fed into the top of the distillation column to react with the sulfur dichloride (180). Commercial thionyl chloride has a purity of 98—99.6% minimum, having sulfur dioxide, sulfur chlorides, and sulfuryl chloride as possible impurities. These can be determined by gas chromatography (181). [Pg.141]

Further routes of cyclizations have been studied in parallel in the case of cis- and rra/J5-2-hydroxymethyl-l-cyclohexylamine (106) (880PP73). The preparation of thiourea or urea adducts 107 and 108 with phenyl isothiocyanate or phenyl isocyanate proceeds smoothly. The reaction of 107 with methyl iodide and subsequent alkali treatment, by elimination of methyl mercaptan, resulted in the iminooxazine 109 in high yields. The ring closures of both cis and trans thiourea adducts to 1,3-oxazines proceed with retention. Cyclodesulfuration of the adduct 107 by mercury(II) oxide or N,N -dicyclohexylcarbodiimide resulted in the iminooxazine 109, but the yield was low and the purification of the product was cumbersome. The ring closure of 108 with thionyl chloride led to the iminooxazine 109 in only moderate yield. [Pg.366]

Previously, Ayyangar and colleagues reported the synthesis of 2-chloroanilide and aniline derivatives by a [3,3]-sigmatropic rearrangement of the adduct obtained by the treatment of hydroxamic acid and hydroxylamine derivatives with thionyl chloride. [Pg.376]

Dibenzocycloheptenone (24-6) also serves as a starting material for the preparation of one of the few medicinal products that contains an acetylenic linkage. Reaction of (24-6) with the Grignard reagent from propargyl bromide leads to the alcohol (27-1). The free proton acetylene is sufficiently acidic for that center to take part in a Mannich reaction. Thus, reaction of (27-1) with formaldehyde and dimethylamine gives the adduct (27-2). Dehydration by means of thionyl chloride completes the synthesis of intriptyline (27-3) [28]. [Pg.108]

Polystyrene-bound allylic or benzylic alcohols react smoothly with hydrogen chloride or hydrogen bromide to yield the corresponding halides. The more stable the intermediate carbocation, the more easily the solvolysis will proceed. Alternatively, thionyl chloride can be used to convert benzyl alcohols into chlorides [7,25,26]. A milder alternative for preparing bromides or iodides, which is also suitable for non-benzylic alcohols, is the treatment of alcohols with phosphines and halogens or the preformed adducts thereof (Table 6.2, Experimental Procedure 6.1 [27-31]). Benzhy-dryl and trityl alcohols bound to cross-linked or non-cross-linked polystyrene are particularly prone to solvolysis, and can be converted into the corresponding chlorides by treatment with acetyl chloride in toluene or similar solvents (Table 6.2 [32-35]). [Pg.208]

The electrochemical technique gave the possibility of obtain the to-acetonitrilc adduct of the tetrachlorides and bromides, except in those cases where gram quantities of tetra-ethylammonium halide were present when the appropriate anionic halogen complexes were obtained. Thionyl chloride proved to be the most satisfactory solvent for the preparation of the anionic chlorocomplexes. [Pg.268]

Molecular halogens react with the thiones to give initially 1 1 adducts, formulated probably as 3-halothio-l,2-dithiolylium halides (42). For chlorine, these types convert to 3-chloro-1,2-dithiolylium salts (35a X = C1) (81AHC(23)i5l, 76PS(i)i85). Other more easily controlled halogen sources may be used, including thionyl chloride, oxalyl chloride, sulfur chloride and phosphorus oxychloride (70LA(742)103). A possible pathway for reaction with oxalyl chloride is shown in Scheme 19. [Pg.801]

Adducts 289 derived from carbonyl compounds and anions 287 behave similarly to bis(phenylsulfanyl)alkyllithium adducts 133 (Scheme 35) when they are treated with thionyl chloride in triethylamine, so 2-alkylidene-l,4-benzodithianes 290 were obtained. However, the treatment with p-toluenesulfonic acid or trifluoroacetic acid afforded products 291 (Scheme 76)457. [Pg.186]

Carbene adducts of a range of sulfur compounds have also been isolated. Carbene (1) (R = i-Pr, R = Me) reacts with sulfur dichloride or thionyl chloride to yield the hyperva-lent sulfur derivatives (118) and (119). Similarly, reaction of carbene (2) (R = r-Bu) with SO2 led to the formation of the 1 1 adduct (2)-SO2 (120). In contrast, reaction of carbene (1) (R = i-Pr, R = Me) with SO2CI2 affords the 2-chloro-l,3-diisopropyl-4,5-dimethylimidazohumchlorosul-fite salt (121). A carbene adduct of SO3 (122) can then be isolated through hydrolysis of (121) in the presence of cyanide. [Pg.5780]

An intramolecular version of this methodology was further applied to construction of amino sugars, such as the unnatural C-5 epimer of desosamine (399) (84JOC3243) and deoxyaminopentose (406) (85T1143). When ( , )-diene carbamate 393 was treated with thionyl chloride/pyridine between 0°C and room temperature, a single Diels-Alder adduct (395) was formed in 80% yield. The structure and stereochemistry of this dihydrothiazine oxide were... [Pg.298]

Thionyl chloride forms a fairly stable primary adduct (15) with DMF, which has been isolated. On heating it decomposes to SO2 and NA -dimethylformamide chloride (equation 4). Treatment of the adduct (15) with carboxylic acids affords iminium salts (16 equation S) in which the carboxylic acid function is strongly activated, e.g. for amide formation. With imines -lactams are formed, sodium azide is converted to acyl azides. ... [Pg.491]


See other pages where Thionyl chloride adducts is mentioned: [Pg.414]    [Pg.2253]    [Pg.818]    [Pg.414]    [Pg.2253]    [Pg.818]    [Pg.128]    [Pg.120]    [Pg.306]    [Pg.215]    [Pg.26]    [Pg.139]    [Pg.562]    [Pg.250]    [Pg.250]    [Pg.260]    [Pg.243]    [Pg.128]    [Pg.442]    [Pg.21]    [Pg.188]    [Pg.190]    [Pg.191]    [Pg.241]    [Pg.128]    [Pg.486]    [Pg.701]    [Pg.218]    [Pg.307]    [Pg.568]    [Pg.249]    [Pg.293]    [Pg.297]    [Pg.701]    [Pg.496]    [Pg.134]    [Pg.267]    [Pg.17]    [Pg.22]   


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