Toluene-/?-sulfonates

Aminomalononitrile toluene-4-sulfonate [5098-14-6] M 253.4, m 168-170 , 172 (dec), pKe 1.3. Colourless crysts on recrystn from MeCN (1.8g in lOOmL) using activated charcoal. Wash the crystals with dry Et20 and dry at 25 /lmm. Recovery of -80%. [Ferris et al. Org Synth Coll Vol V 32 7973.]... 

Isomer-free toluene-4-sulfonic (2.5-3) 1 at 110°-120°C in liquid phase followed by treatment of the reaction mixture with gaseous toluene at 130-150°C Produced by recrystallization 166... 

The transport of toluene-4-sulfonate into Comamonas testosteroni has been examined (Locher et al. 1993), and rapid uptake required growth of the cells with toluene-4-sulfonate or 4-methylbenzoate. From the results of experiments with various inhibitors, it was concluded that a toluenesulfonate anion/proton symport system operates rather than transport driven by a difference in electrical potential (A (/), and uptake could not take place under anaerobic conditions unless an electron acceptor such as nitrate was present. 

Methylation of 3-hydroxy-5-phenyl-l,2,4-thiadiazole (23) with dimethyl sulfate and sodium hydroxide at room temperature gives the N-2 compound (24). When methylation is carried out using methyl toluene-4-sulfonate at 100°C compound (24) and the meso-ionic derivative (25) are produced (Scheme 7) <84JCS(Pl)75>. 

Molybdate or tungstate were introduced by ion exchange with solutions of the Na+ salts under N2 atmosphere at a pH of 10 (for Mg,Al-LDH) or 7 (for Zn,Al-LDH). Organophilic LDHs were prepared by ion exchange with a double excess (with respect to the anion exchange capacity) of the Na+ salts of toluene-4-sulfonate and dodecyl sulfate. 

Lithium aluminum hydride Toluene-4-sulfonic acid but-3-ynyl ester Methyliodide... 

A mixture of 9,9-dimethyl-2, 5-dihydroxy-6,7-benzomorphan hydrochloride, calcium carbonate and toluene-4-sulfonic acid but-3-ynyl ester in dimethylformamide is heated and subsequently concentrated under reduced pressure. The residue is taken up in a mixture of water and chloroform (1 1) and the aequeous phase extracted twice with chloroform/butanol (9 1). The combined organic phases are concentrated under reduced pressure to give the... 

Oxidation of 2-substituted 3,6-dihydro-2//-thiopyrans with MCPBA gives a mixture of the cis and trans sulfoxides which is dehydrated on heating with toluene-4-sulfonic acid to give good yields of the 2//-thiopyrans (Scheme 117) <2001J(P1)2269>. 

Preparation of toluene-4-sulfonic acid 7,8-dihydro-6H-5-oxa-l-aza-phenanthren-6-yl-methyl ester... 

The unbridged and uncondensed oxazocine 112 was obtained as mixture of diastereomers, in 58% yield, upon refluxing the amino alcohol 248 with phenylselanylacetaldehyde diethyl acetal and a catalytic amount of pyridinium toluene-4-sulfonate (Equation 26) <1995J(P1)123>. 

SYNS METHYLESTER KYSELINY p-TOLUEN-SULFONOVE (CZECH) METHYL-4-METHYLBENZ-ENESULFONATE METHYL-p-TOLUENESULFONATE METHYL TOLUENE-4-SULFONATE D METHYL TOS i LATE METHYL-p-TOS i LATE p-TOLUOL-SULFONSAEURE METHYL ESTER (GERMAN)... 

Methylation of the 2-thio analogue of xanthine (129) at 170 °(i gave a quaternary salt which with ammonia afforded the betaine (130) in which both 5- and A-methylation has occurred. The analogous compound (131) is similarly produced as a toluene-4-sulfonate salt from 2-amino-6-thioxo-l,6-dihydropurine and methyl toluene-4-sulfonate (62JA1914). 

Alkylthiopurines may also undergo Mannich and Michael addition reactions. Thus 6-methylthiopurine with formaldehyde and I se ve 9-hydroxymethyl-6-methylthiopurine (67JMC104), and dihydrofuranylation of 2-acetamido-6-benzylthiopurine occurs in the presence of toluene-4-sulfonic acid and 2,3-dihydrofuran to give 2-acetamido-6-benzylthio-9-(tetrahydrofur-2-yI)purine (63JMC471). 

Hydrogenolysis of the toluene-4-sulfonate of an alcohol may be carried out with a nucleophilic hydride such as lithium aluminium hydride. There are also a series of radical methods based on the reduction of alkyl halides with tri- -butyltin hydride (BUjSnH). Finally, the source of the hydrogen may be the electrophilic proton, exemplified by the decomposition of organometallic reagents such as the Grignard reagent with water. 

Many of the convenient methods of preparing alkyl halides are based on the reactions of alcohols with reagents such as thionyl chloride and phosphorus pentachloride. These are dealt with in more detail in Section 2.3 on alcohols. The nucleophilic substitution of an alkyl methanesul-fonate or toluene-4-sulfonate with a sodium or potassium halide is a useful method. 

Alkoxides are nucleophiles and may be used to react with alkyl hahdes or alkyl toluene-4-sulfonates to form ethers (Scheme 2.1 Ic). 

The sulfonyl halides (ArSOjCl) convert the alcohol into a sulfonate (ArSOjOR), which is a better leaving group than the hydroxyl group. This allows a range of nucleophilic substitutions to be carried out, many of which parallel those found with alkyl halides. Alkyl halides such as iodides are formed by the nucleophilic substitution of the sulfonate by an iodide ion. The reaction in this case proceeds with inversion of configuration. Treatment of the sulfonate esters with bases such as sodium methoxide or collidine (2,4,6-trimethylpyridine), or even just heating them, can lead to the elimination of toluene-4-sulfonic acid and the formation of an alkene. 

Amines can displace a halide or a derivative of an alcohol, such as the methanesulfonate or toluene-4-sulfonate, with the eventual formation of a quaternary ammonium salt. Reaction with ammonia may lead to mixtures, since the initial alkylation increases the basicity of the nitrogen, and hence the primary amine reacts more rapidly than ammonia. Further reaction, although enhanced by the increase in basicity, may be impeded by steric hindrance arising from the additional alkyl groups. 

Anion effects can be important in the solid state. Thus, tri-capped trigonal prismatic [Sc(H20)9]3+ is found in the X-ray structure of the CF3S03 salt. In Sc(pts)3-6I I20, four waters and two pts (toluene-4-sulfonate) anions are coordinated, and six coordination appears to be adopted in chloro-aqua complexes. Clearly, coordination numbers of 6 9 can be adopted with little trouble. Acid dissociation gives ScOH2+(aq) (pATa 4.8 I =0.1 MC104 ). 

---