4-Methylbenzenesulfonic acid

TosOH 4-methylbenzenesulfonic acid = p toluenesiilfonic acid, tosic acid X, Y leaving groups. e.g., halogen, RSOj, in substitution and elimination reactions... 

Chemical Designations - Synonyms Methylbenzenesulfonic acid Tosic acid p-TSA Chemical Formula CH3CjH4S03H. 

S)-2-[(f )-l-Alkyl-2-isoquinolinyl]-4,5-dihydro-4-isopropyloxazole is added to a solution of hydrazine hydrate in ethanol (0.5 mL/mmol) containing a catalytic amount of 4-methylbenzenesulfonic acid and is refluxed under nitrogen for 4-6 h, concentrated in vacuo, and the residue is treated with 10% aq potassium hydroxide. The mixture is extracted with CH2C12, dried over MgS04, evaporated and purified by radial chromatography. 

A solution containing 4.33 g (42 mmol) of (S)-2-amino-3-methylbutanol [(S)-valmol], 7.6 g (42 mmol) of y-oxobenzenebutanoic acid and 100 mg of 4-methylbenzenesulfonic acid in 150 mL of toluene is heated under reflux with azeotropic removal of water. After 8 h the mixture is cooled and the solvent removed in... 

The cleavage of a,a -disubstituted SAMP- or RAMP-hydrazones to spiroacetals is performed without racemization under acidic conditions (4-methylbenzenesulfonic acid in chloroform) by careful monitoring of the reaction by thin layer chromatography and immediate workup of the reaction after completion in order to avoid racemization. Racemic mixtures are obtained when the reaction mixture is stirred for a longer time20. 

LltholRubine. Lithol Rubine (Pigment Red 57 [5281-04-9]), also referred to as 4B toner, is the calcium salt of diazotized 2-amino-5-methylbenzenesulfonic acid coupled with 3-hydroxy-2-naphthoic acid. It ranks high among organic pigments in production volume and use. 

Methylanthranilic acids, a211, a212 TV- Methy 1 anthran i 1 ic acid, ml 17 Methylbenzene, tl67 4-Methylbenzenesulfonic acid, tl76... 

Methyl-5-aminobenzenesulfonic acid 2- Methylbenzenesulfonic acid (59%) + 2-methyl-5-ethoxybenzenesulfonic acid (37%) 21... 

Amino-5-methylbenzenesulfoiiic acid 3-Methylbenzenesulfonic acid CuSO added. It appears to be of value in this instance. 70, 176... 

Diphenylthieno[2,3-c]furan (130) reacted with 7V-4-methylphenylmaleimide at room temperature to give in 73% yield endo adduct (131). In the presence of 4-methylbenzenesulfonic acid the substituted benzo[6]thiophene derivative (132) was obtained. Vinylene carbonate as dienophile led to an endo/exo mixture (133a) and (133b) in the ratio 6 1. The same reaction in the presence of sulfuric and acetic acids afforded compound (134) <89CB1U9). 

Methyl 2-formyl-4-methylfuro[3,2-6]pyrrole-5-carboxylate (86) with 2,6-dialkylphenylhydrazines and a catalytic amount of 4-methylbenzenesulfonic acid in refluxing toluene gave the hydrazones (248)-(250). Analogously (V,A-dimethylhydrazone (251) was made from (V,(V-dimethylhydrazine. 

Methyl chlorocarbonate Formic acid, chloro-, methyl ester (8) Carbonochloridlc acid, methyl ester (9) (79-22-1) letraethylammonlum p-toluenesulfonate Ammonium, tetraethyl-, p-toluenesulfonate (8) Ethanammium, N,N,N-triethyl-, salt with 4-methylbenzenesulfonic acid (1 1) (9) (733-44-8)... 

Order of Elution (1) Cresidinesulfonic acid (CSA) (2) unknown (3) Schaeffer s salt (SS) (4) unknown (5) 4,4 -diazoaminobis(5-methoxy-2-methylbenzenesulfonic acid) (DMMA) (6) unknown (7) Allura Red (8) 6,6 -oxybis(2-naphthalenesulfonic acid) (DONS). 

Formic acid Methanesulfonic acid 4-Methylbenzenesulfonic acid... 

Stereoselective synthesis of the substituted 1,7-dioxaspiro[5.5]undecane 2 has been performed by a simple treatment of the 3,4-dihydro-2//-pyran 1 with 4-methylbenzenesulfonic acid/water in benzene at 55 °C for 3 hours. The cydization proceeds with total stereoselectivity and only one isomer is recovered in 55% yield. The corresponding unprotected spiroketal can be obtained as a single diastereomer and the structure is determined on the basis of H-NMR data98. 

A spiroketal is also obtained in low stereoselectivity by addition of a hydroxy group to the double bond of a pyrone with acidic catalysis. Thus, treatment of 3 with 4-methylbenzenesulfonic acid in tetrahydrofuran/water at 65 C for 2 hours, and then with trifluoroacetic acid in benzene at 20 °C, gives a good yield of the corresponding spiroketals in a 67 33 diastereomeric mixture ". 

Effective aminoselenenylation of alkenes occurs on treatment with iV-(phenylseleno)phthal-imide (A -PSP) and cyanamide in the presence of 4-methylbenzenesulfonic acid (see overleaf)61. 

Amidals 1 were prepared by the reaction of secondary allylic alcohols with benzyl hydroxy-methylcarbamate in dichloromethane using 4-methylbenzenesulfonic acid as a catalyst. The cyclization proceeded by treating 1 with mercury(II) acetate (1.25-2.0 equiv) in acetonitrile at 20 °C for 12 hours, followed by addition of sodium acetate and sodium borohydride to give the corresponding oxazolidine 2 in 60-90% yield158. 

C7H803 methyl 2-methyl-3-furancarboxylate 6141-58-8 474.75 41.463 2 11017 C7H9N03S 5-amlno-2-methylbenzenesulfonic acid 118-88-7 773.15 70.660 1,2... 

C6H140 2-methyl-1-pentanol 105-30-6 gas 1.481 2 10914 C7H803S 2-methylbenzenesulfonic acid 88-20-0 gas 4.137 2... 

The 2-oxazolinylphenyl methyl tellurium was converted to methyl 2-(2 -methyl-2 -toluenesulfonylamino-r-propyloxycarbonyl)phenyl tellurium when treated with a refluxing aqueous solution of 4-methylbenzenesulfonic acid. ... 

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