N-Butyl p-toluenesulfonate

Esters of aliphatic and aromatic sulfonic acids are conveniently prepared in high yields from alcohols and sulfonyl halides. A basic medium is required. By substituting sodium butoxide for sodium hydroxide in butanol, the yield of n-butyl p-toluenesulfonate is increased from 54% to 98%. Ethyl benzenesulfonate and nuclear-substituted derivatives carrying bromo, methoxyl, and nirro groups are prepared from the corresponding sulfonyl chlorides by treatment with sodium ethoxide in absolute ethanol the yields are 74-81%. Pyridine is by far the most popular basic medium for this reaction. Alcohols (C -Cjj) react at 0-10° in 80-90% yields, and various phenols can be converted to aryl sulfonates in this base. "... 

C11H16O3S, n-Butyl p-toluenesulfonate 67 CiiHsiBr02, 11-Bromoundecanoic acid 62... 

Anhydrous p-to uenesulfonic acid, excess n-butyl ether, and tetrachlorethane heated 10 hrs. at 160° with azeotropic entrainment of the resulting water n-butyl p-toluenesulfonate. Y 74%. F. e. s. D. Klamann and P. Weyerstahl, B. 98, 2070 (1965). 

Prepare 6-methoxy-l-indanone (I) (JCS 1986(1962)) using polyphosphoric acid made by diluting 500 g of the commercial acid with 120 g 85% phosphoric acid. 2.5 g (I) in 176 ml ether and reflux one hour with 0.27 g lithium aluminum hydride. Cool and carefully add water and filter when bubbling stops (can use Celite filter aid). Dry and evaporate in vacuum and store twelve hours at -15° (under N2 if possible) to precipitate the white 6-methoxy-l-indanol (II) (recrystallize-n-hexane). 2.5 g (II) in 73 ml benzene and reflux one-half hour with 0.2 g p-toluenesulfonic acid. Cool, add water and separate the phases. Extract the aqueous phase with ether and combine with benzene phase and dry, evaporate in vacuum to get 5-methoxy-indene (III) (can distill 110-45/10). 1.53 g (III) and 1.39 g N.N-diethyl-aminoethyl-Cl.HCI in benzene (prepare the free base in benzene as described previously). Reflux four hours with 0.42 g sodamide, cool, wash with water and dry, evaporate in vacuum to get the indene analog of 6-methoxy DET as a dark liquid (can crystallize as oxalate). Alternatively, dissolve 2.51 g (III) in ether and treat (under N if possible) with 12 ml 1.6M buty-Li in hexane at 0-10°. After two hours cool to -30° and add 12 ml more of butyl-Li. Add ether suspension of 2.5 g N,N-diethylaminoethyl-CI. HCI over one-half hour and warm to room temperature. Filter, evaporate in vacuum to get the 6-methoxy-DET analog. 

To a mixture of 1-methoxy-l,3-butadiene (1 55.3 g, 0.66 mol) [43] and n-butyl glyoxylate (86.0 g, 0.66mol) [44], 0.1 g hydroquinone was added and the solution was refluxed at 100°C for 6 h under argon. Distillation at 88°-90°C/0.5 tonr gave 2 (R = Bu) (91.6 g, 65%) as a pale-yellow liquid with a faint odor. By gas chromatography this product is a mixture of cis and trans (ca. 7 3) isomers. Treatment of the isomer mixture in dichloro-methane solution with p-toluenesulfonic acid or zinc chloride for 2 h leads to an almost pure trans-isomer (ca. 95%). 

NMO NMP Nu PPA PCC PDC phen Phth PPE PPTS Red-Al SEM Sia2BH TAS TBAF TBDMS TBDMS-C1 TBHP TCE TCNE TES Tf TFA TFAA THF THP TIPBS-C1 TIPS-C1 TMEDA TMS TMS-C1 TMS-CN Tol TosMIC TPP Tr Ts TTFA TTN N-methylmorpholine N-oxide jV-methyl-2-pyrrolidone nucleophile polyphosphoric acid pyridinium chlorochromate pyridinium dichromate 1,10-phenanthroline phthaloyl polyphosphate ester pyridinium p-toluenesulfonate sodium bis(methoxyethoxy)aluminum dihydride (3-trimethylsilylethoxy methyl disiamylborane tris(diethylamino)sulfonium tetra-n-butylammonium fluoride f-butyldimethylsilyl f-butyldimethylsilyl chloride f-butyl hydroperoxide 2,2,2-trichloroethanol tetracyanoethylene triethylsilyl triflyl (trifluoromethanesulfonyl) trifluoroacetic acid trifluoroacetic anhydride tetrahydrofuran tetrahydropyranyl 2,4,6-triisopropylbenzenesulfonyl chloride 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane tetramethylethylenediamine [ 1,2-bis(dimethylamino)ethane] trimethylsilyl trimethylsilyl chloride trimethylsilyl cyanide tolyl tosylmethyl isocyanide meso-tetraphenylporphyrin trityl (triphenylmethyl) tosyl (p-toluenesulfonyl) thallium trifluoroacetate thallium(III) nitrate... 

Potassium cyanide has been caused to react with salts and esters of sulfonic acids to give nitriles. Thus, an intimate mixture of finely powdered potassium cyanide with the compound may be fused 422 this method was successfully applied428 to tetrahydrofurfuryl p-toluenesul-fonate and methanesulfonate, but failed with l,2 3,4-di-0-isopropylidene-6-O-tosyl-D-galactose. Another method, consisting of treatment of the ester with a stirred, boiling, saturated, aqueous solution of potassium cyanide gave885 a 70 to 83% yield of nitrile with primary p-toluenesul-fonates (ethyl, n-butyl, and n-octyl) and a 43% yield with a secondary p-toluenesulfonate (isopropyl). Similar methods had been applied earlier98 841 to such simple esters, but have not apparently found use with sulfonic esters of carbohydrates. 

Moreover, the formation of enoxy-silanes via silylation of ketones127 by means of N-methyl-N-TMS-acetamide (1 72) in presence of sodium trimethylsilanolate (173) was reported in 1969 and since then, the use of silylating reagents in presence of a catalyst has found wide appreciation and growing utilization as shown in recent papers128-132 (Scheme 27). Diacetyl (181) can be converted by trifluoromethylsul-fonic acid-TMS-ester (182) into 2,3-bis(trimethylsiloxy)-l, 3-butadiene (7treatment with ethyl TMS acetate (7 5)/tetrakis(n-butyl)amine fluoride l-trimethylsiloxy-2-methyl-styrene (i<56)130. Cyclohexanone reacts with the combination dimethyl-TMS-amine (18 7)/p-toluenesulfonic acid to 1-trimethylsiloxy-l-cyclohexene (iSS)131. Similarly, acetylacetone plus phenyl-triethylsilyl-sulfide (189) afford 2-triethylsiloxy-2-pentene-4-one (790)132. ... 

From Di-m-butyl Formal. When 2-butyne-l,4-diol and di-n-butyl formal were allowed to react as described above, in the presence of a catalytic amount of p-toluenesulfonic acid at temperatures up to 190° C., nearly two equivalents of n-butyl alcohol distilled off. The product was a mushy, light brown solid of molecular weight 475, as determined cryoscopically in benzene. 

Acetylation of alcohols and phenols by ketene has limited use. Unless apparatus for the preparation of ketene is readily available, less troublesome methods can usually be found. Worthy of mention, however, are the acetylations of lactic esters in 94-98% yields and of tertiary alcohols and phenols in 89-96% yields.Catalysts are necessary even to convert a high percentage of n-butyl alcohol to n-butyl acetate. Sulfuric and p-toluenesulfonic acids are commonly used. Certain aldehydes and ketones are attacked by ketene. Acetates of enol forms of ketones may be made in this way. ° Under certain conditions / -lactones are formed (cf. method 327),... 

The following chemicals were purchased from Kanto Chemical Co. Inc. and used as received neopentyl glycol, p-toluenesulfonic acid, sodium, and n-BuLi. N,N,N, N -Tetramethylethylenediamine was purchased from Aldrich Chemical Company, Inc. and distilled before use. 1,3-Dichloroacetone was obtained from Wacker Chemicals East Asia and used as received. Reagent grade benzene, pentane, ether, THE, tert-butyl alcohol, acetonitrile, and toluene were purchased from Wako Chemicals Industries Ltd. Benzene, pentane, and tert-butyl alcohol were distilled from CaH ether and THF from sodium benzophenone ketyl immediately before use acetonitrile successively from PjOj and anhydrous KjCOj and toluene from LiAlH. Potassium tert-butoxide and 2-cyclopenten-1-one were purchased from Tokyo Kasei Kogyo Co. Ltd. the ketone was distilled before use. 

CyclopropanecarboxaUehytte. Dehydration of a mixture of cis- and froni-cyclo-butane-l,2-diol (I) with boron trifluoride n-butyl etherate at 230° yields cyclopropane-carboxaldehyde (2) in 65-80% yield. Dehydration of (I) with p-toluenesulfonic acid gives (2) in somewhat lower yields (66%)- ... 

Enol acetylation (I, 1174 1178). As a Grst step in the synthesis of 3-n-butyl-2,4-pentanedione, a mixture of 28.6 g. (0.25 mole) of 2-heptanone, 51.0 g. (0.50 mole) of acetic anhydride, and 1.9 g. (0.01 mole) of p-toluenesulfonic acid monohydrate contained in a stoppered 500-ml. round-bottomed flask equipped with a magnetic stirrer is stirred at room temperature for 30 min. Then 55 g. (0.43 mole) of the I 1 boron trifluoridc-acetic acid complex [Reagents, I, 69 (1967)] is added some heat is evolved... 

Benzenesulfonate or p-toluenesulfonate esters of 1,3 glycols frequently give better yields of thietanes than the 1,3-dihalides. Sodium sulfide in dimethyl sulfoxide, diethylene glycol, " aqueous n-butyl alcohol, 1,2-... 

Dibutyl Formal. The compound was prepared by refluxing a mixture containing 5.0 moles of formaldehyde, 11 moles of butyl alcohol, 25 grams of p-toluenesulfonic acid, and 500 ml. of benzene. The water which was formed during the reaction was collected in a Dean-Stark trap attached to a Vigreux column. This required about 4 hours. The solution was then cooled, washed with sodium bicarbonate solution, dried with sodium sulfate, and distilled. The product, a colorless liquid, boiled at 55° C., 6 mm. of Hg, n 1.4061. The yield was about 80%. 

Addition to a,p-unsaturated ethers. In the presence of a catalytic amount of p-toluenesulfonic acid, isocyanic acid adds to vinyl n-butyl ether to give 1-butoxy-ethyl isocyanate in high yield. ... 

Peptide synthesis. An N-protected amino acid (I) is easily converted into the t-butyl ester (2) by reaction with excess isobutene in the presence of sulfuric acid or p-toluenesulfonic acid. Removal of the N-proicciivc group by hydrogenolysis... 

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