Thionyl reaction

By the action of thionyl chloride upon the alcohol alone or mixed with pyridine (to absorb the hydrogen chloride formed in the reaction), for example ... 

The dichlorides of aliphatic glycols are obtained by reaction with thionyl chloride in the presence of a small quantity of pyridine, for example ... 

Fit up the apparatus shown in Fig. Ill, 31, 1 the capacity of the Claisen flask should be 100 ml. Place 40 g. (24-6 ml.) of redistilled thionyl chloride in the flask and 60 g. (62 ml.) of dry n-butyl alcohol (b.p. 116-117°) in the dropping funnel. Cool the flask in ice and add the n-butyl alcohol, with frequent shaking, over 1 hour (1). Reflux the mixture gently for 1 hour to complete the reaction and to remove the residual hydrogen chloride. Arrange the apparatus for distillation, and distil under normal pressure until the temperature rises to 120° then distil under diminished pressure (Fig. 11, 20, 1) and collect the di-n-butyl sulphite at 116-118°/20 mm. The yield is 66 g. 

Place 1 0 g. of the monobasic acid and 2 g. of aniline or p-toluidine in a dry test-tube, attach a short air condenser and heat the mixture in an oil bath at 140-160° for 2 hours do not reflux too vigorously an acid that boils below this temperature range and only allow steam to escape from the top of the condenser. For a sodium salt, use the proportions of 1 g. of salt to 1 5 g. of the base. If the acid is dibasic, employ double the quantity of amine and a reaction temperature of 180-200° incidentally, the procedure is recommended for dibasic acids since the latter frequently give anhydrides with thionyl chloride. Powder the cold reaction mixture, triturate it with 20-30 ml. of 10 per cent, hydrochloric acid, and recrystallise from dilute alcohol. 

Place 29 g. of n-caproamide (Section 111,109) into a 200 ml. distilling flask, and assemble the apparatus shown in Fig. Ill, 28, 1. Remove the trap momentarily and introduce 45 g. (27-5 ml.) of redistilled thionyl chloride no apparent reaction takes place in the cold. Warm the mixture on a water bath or by means of a small flame for 1 hour. Arrange the apparatus for distillation and distil oflF the excess of thionyl chloride (t.c., until the temperature reaches about 90°) and allow to cool. When cold, transfer the residue to a 100 ml. distilling flask (1). Distil from an air bath (Fig. II, 5, 3) the n-capronitrile passes over at 161-163° (2). The yield is 21 g. 

The Y-phenylbutyric acid is cyclised to a-tetralone by converting it into the acid chloride with thionyl chloride or phosphorus pentachloride and then an intramolecular Friedel and Crafts reaction is carried out ... 

CAUTION. The preparation of o-nitrobenzoyl chloride, o-nitrophenacetyl chloride and all o nitroacid chlorides should not be attempted by the above methods a violent explosion may occur upon distilling the product or when the last traces of thionyl chloride are removed in vacuo at 100°. Perhaps the safest method is to treat the pure acid in benzene solution with 1 1 mols of thionyl chloride and to reflux until evolution of sulphur dioxide and hydrogen chloride has ceased the solution of the acid chloride in benzene may then bo employed for most reactions. 

Ethyl nicotiiiate may be prepared either by direct esterification of the acid with ethanol and sulphuric acid, followed by pouring into water and rendering ammoiilacal or by interaction of the acid with thionyl chloride, followed by reaction of nlcotiiiyl chloride hydrochloride with ethanol and subsequent neutralisation. 

Tetrahydrofurfuryl chloride. Place 204 g. (194 ml.) of freshly distilled tetrahydrofurfuryl alcohol (b.p. 177°) and 174 g. (178 ml.) of dry pyridine in a 1-litre three-necked flask, fitted with a dropping funnel, mechanical stirrer and thermometer. Cool in an ice bath, stir vigorously and add 250 g. (153 ml.) of freshly distilled thionyl chloride at the rate of 3-5 drops per second. A pasty crystalline mass begins to separate and the temperar ture commences to rise rapidly when one-third to one-half of the thionyl chloride has been added subsequently the mass largely redissolves and a dark brown liquid forms. Remove the ice bath when the addition is complete and stir the mixture for 3-4 hours. Pour the reaction product into a large separatory funnel and extract with seven 250 ml. portions of ether break up any lumps that may form with a glass rod. Remove the ether from the combined extracts by distillation, wash the residue with three 50 ml. portions of water, dry with anhydrous magnesium sulphate and distil under reduced pressure. The yield of tetrahydrofurfuryl chloride, b.p. 47-48°/15 mm., is 180 g. 

Thionyl chloride (11.5g, 96.4 mmol) was added to 2-nitrophenylacetic acid (8.72g, 48.2mmol) and the suspension was warmed to 50°C and stirred until gas evolution was complete. The resulting solution was concentrated in vacuo and the residue dissolved in CHjClj (30 ml). This solution was added dropwise to a stirred solution of Meldrum s acid (6.94 g, 48.2 mmol) in CH2CI2 (200 ml) under nitrogen at 0 C. The solution was stirred at 0" C for 1 h after the addition was complete and then kept at room temperature for an additional hour. The reaction solution was then worked up by successively washing with dil. HC1, water and brine and dried (MgSOJ. The dried solution was concentrated in vacuo and abs. ethanol (200 ml) was added to the residue. The mixture was... 

DihaIogenothiazoIes (271) thus can be prepared from sodium acetylaminomethane sulfonate (270) and thionyl halide, but this reaction proceeds in low yield. With X — Cl, the yield is 20%, while with X = Br the yield decreases to 2% (Scheme 140). 

Hydroxyalkylthiazoles are also obtained by cyclization or from alkoxyalkyl-thiazoles by hydrolysis (36, 44, 45, 52, 55-57) and by lithium aluminium hydride reduction of the esters of thiazolecarboxylic acids (58-60) or of the thiazoleacetic adds. The Cannizzaro reaction of 4-thiazolealdehyde gives 4-(hydroxymethyl)-thiazole (53). The main reactions of hydroxyalkyl thiazoles are the synthesis of halogenated derivatives by the action of hydrobroraic acid (55, 61-63), thionyl chloride (44, 45, 63-66), phosphoryl chloride (52, 62, 67), phosphorus penta-chloride (58), tribromide (38, 68), esterification (58, 68-71), and elimination that leads to the alkenylthiazoles (49, 72). 

The acid function of an aliphatic chain bonded to a thiazole ring can be esterified. The corresponding acid chloride can also be prepared by the action of thionyl chloride, though the reaction is often accompanied by secondary reactions and gives poor yields (49, 74). 

The normal acid chloride is obtained by reaction between equimolar quantities of acid and thionyl chloride in the presence of pyridine at 0 C. 

Thionyl chloride reacts with alcohols to give alkyl chlorides The inorganic byprod nets m the reaction sulfur dioxide and hydrogen chloride are both gases at room tern perature and are easily removed making it an easy matter to isolate the alkyl chloride... 

Because tertiary alcohols are so readily converted to chlorides with hydrogen chlo nde thionyl chlonde is used mainly to prepare pnmary and secondary alkyl chlondes Reactions with thionyl chlonde are normally carried out m the presence of potassium carbonate or the weak organic base pyndme... 

Thionyl chloride and phosphorus tribromide are specialized reagents used to bring about particular functional group transformations For this reason we won t present the mechanisms by which they convert alcohols to alkyl halides but instead will limit our selves to those mechanisms that have broad applicability and enhance our knowledge of fundamental principles In those instances you will find that a mechanistic understand mg IS of great help m organizing the reaction types of organic chemistry... 

Reaction of alcohols with thionyl chloride (Section... 

Acyl chlorides are readily available They are prepared from carboxylic acids by reaction with thionyl chloride... 

Reaction with thionyl chloride (Sec tion 4 13) Thionyl chloride converts alcohols to alkyl chlorides... 

Both reactants m the Williamson ether synthesis usually originate m alcohol pre cursors Sodium and potassium alkoxides are prepared by reaction of an alcohol with the appropriate metal and alkyl halides are most commonly made from alcohols by reaction with a hydrogen halide (Section 4 7) thionyl chloride (Section 4 13) or phosphorus tri bromide (Section 4 13) Alternatively alkyl p toluenesulfonates may be used m place of alkyl halides alkyl p toluenesulfonates are also prepared from alcohols as their imme diate precursors (Section 8 14)... 

Acetyl chlotide was formerly manufactured by the action of thionyl chlotide [7719-09-7], CI2OS, on gray acetate of lime, but this route has been largely supplanted by the reaction of sodium acetate or acetic acid and phosphoms ttichlotide [7719-12-2] (24). A similar route apparently is stiU being used in the Soviet Union (25). Both pathways ate inherently costly. 

Jicyylic anhydride is formed by treatment of the acid with acetic anhydride or by reaction of acrylate salts with acryloyl chloride. Jicryloylchloride is made by reaction of acryhc acid with phosphorous oxychloride, or benzoyl or thionyl chloride. Neither the anhydride nor the acid chloride is of commercial interest. 

Reaction with Sulfur Electrophiles. Bisa2iridine compounds can be prepared from sulfur dichloride, thionyl chloride, or sulfuryl chloride... 

A simpler nonphosgene process for the manufacture of isocyanates consists of the reaction of amines with carbon dioxide in the presence of an aprotic organic solvent and a nitrogeneous base. The corresponding ammonium carbamate is treated with a dehydrating agent. This concept has been apphed to the synthesis of aromatic and aUphatic isocyanates. The process rehes on the facile formation of amine—carbon dioxide salts using acid haUdes such as phosphoryl chloride [10025-87-3] and thionyl chloride [7719-09-7] (30). 

Acid Chloride Formation. Monoacid chlorides of maleic and fumaric acid are not known. Treatment of maleic anhydride or maleic acid with various reagents such as phosgene [75-44-5] (qv), phthaloyl chloride [88-95-9] phosphoms pentachloride [10026-13-8] or thionyl chloride [7719-09-7] gives 5,5-dichloro-2(5JT)furanone [133565-92-1] (4) (26). Similar conditions convert fumaric acid to fumaryl chloride [627-63-4] (5) (26,27). NoncycHc maleyl chloride [22542-53-6] (6) forms in 11% yield at 220°C in the reaction of one mole of maleic anhydride with six moles of carbon tetrachloride [56-23-5] over an activated carbon [7440-44-4] catalyst (28). 

Derivatives. In general, the esters of terephthaHc acid derived from saturated alcohols undergo the same reactions as dimethyl terephthalate. Some physical properties of six of these esters are Hsted in Table 23. The di- -butyl and di-2-ethyIhexyl esters find use as plasticizers (qv). Terephthaloyl chloride, which is prepared by reaction of terephthaHc acid and thionyl chloride, is used to prepare derivatives of terephthaHc acid. 

Sahcyhc acid can be converted to sahcyloyl chloride [1441 -87-8] hy reaction with thionyl chloride in boiling ben2ene. The formation of acyl haUde may also extend to reaction with the phenoHc hydroxyl. The reaction with phosphoms tri- and pentachlorides is not restricted to the formation of the acid chloride. Further interaction of the phosphoms haUde and the phenoHc hydroxyl results in the formation of the phosphoric or phosphorous esters. 

Sulfamoyl chloride [7778 2-9] forms from reaction with thionyl chloride (15,16) ... 

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