p -Toluenesulfonic acid methyl ester

Structural formula
General
Surname	p -Toluenesulfonic acid methyl ester
other names	Methyl p -toluenesulfonate; Methyl tosylate; 4-methylbenzenesulfonic acid methyl ester;
Molecular formula	C 8 H 10 O 3 S
Brief description	colorless to pale yellow solid
External identifiers / databases
EC number	201-283-5
ECHA InfoCard	100.001.167
PubChem	6645
Wikidata	Q25616437
properties
Molar mass	186.23 g mol −1
Physical state	firmly
density	1.234 g cm −3 at 20 ° C
Melting point	25 - 28 ° C ; 28-29 ° C ;
boiling point	140 ° C at 20 mmHg; 144 - 145 ° C at 7 hPa; 292 ° C at 760 mmHg;
Vapor pressure	1 hPa at 20 ° C
solubility	almost insoluble in water, slightly soluble in petroleum ether and diethyl ether , soluble in ethanol , benzene and chloroform
safety instructions
H and P phrases	H: 302-314-317
	P: 280-305 + 351 + 338-310
Toxicological data	341 mg kg −1 ( LD 50 , rat , oral ) ; 250 mg kg −1 ( LD 50 , rat , sc ) ;
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Methyl p -toluenesulfonate (methyl tosylate) isthe simplest tosylate as a methyl ester of p -toluenesulfonic acid , which is used as a methylating agent and catalyst for alkyd resins and as an initiator for the polymerization of substituted oxazolines to poly (2-oxazolines) n .

Occurrence and representation

The reaction of para- toluenesulphonic acid chloride with methanol in the presence of pyridine to neutralize the hydrogen chloride formed gives p -toluenesulphonic acid methyl ester in 70% yield.

With solid potassium carbonate as the acid scavenger, methyl tosylate is obtained in 96% yield.

p- Toluenesulfonic acid reacts with trimethyl orthoformate at room temperature after 14 hours or under reflux for 30 minutes in 99% yield to form p -toluenesulfonic acid methyl ester.

In the presence of Fe ³⁺ -containing montmorillonite , p -toluenesulfonic acid also reacts with methanol to form the sulfonic acid ester in 84% yield.

Instead of the solid catalyst montmorillonite, the solid silica chloride (from silica gel and thionyl chloride ) can also be used for this esterification.

properties

methyl p -toluenesulfonate is a colorless to pale yellow crystalline solid that is insoluble in water and soluble in some organic solvents.

Applications

p -Toluenesulfonic acid methyl ester is like other tosylates (RO-SO ₂ -Phenyl-CH ₃ ) a reactive methylating agent and transfers methyl groups to nucleophilic compounds such. B. alcohols, phenols, amines or thiols.

An example of the alkylation of a basic nitrogen compound with methyl tosylate is the methylation of 3,6-bis (acetylamino) acridine to give 3,6-bis (acetylamino) -10-methylacridinium tosylate, from which the antiseptic acriflavinium chloride is obtained by means of hydrogen chloride .

Another example is the methylation of 2-methylbenzothiazole to the corresponding N-methylammonium tosylate , which reacts to a blue cyanine dye after exchanging the tosylate anion for the tetrafluoroborate anion and reacting with the Koenig's salt .

Methyl p- toluenesulfonate is used to prepare quaternized alkyl ketene dimers (AKD) derivatives (long-chain alkylamidoamines), which are used as water repellants for paper or for the crease-free finishing of textiles.

In terms of both atom economy and economy, methyl tosylate is mostly inferior to the cheaper methylating agents methyl chloride and dimethyl sulfate for quaternization reactions, despite its higher reactivity .

More recently, methyl tosylate has been used as an initiator for the polymerization of 2-alkyloxazolines, such as. B. 2-Ethyl-2-oxazoline found

which are discussed as versatile materials for biomedical applications, especially because of their high biocompatibility .

Individual evidence

↑ ^a ^b ^c ^d ^e ^f data sheet methyl p-toluenesulfonate from Sigma-Aldrich , accessed on May 30, 2016 ( PDF ).
↑ ^a ^b ^c Entry on Methyl p-Toluenesulfonate at TCI Europe, accessed on May 30, 2016.
↑ ^a ^b ^c ^d data sheet methyl p-toluenesulfonate, 98% from AlfaAesar, accessed on May 30, 2016 ( PDF )(JavaScript required) .
↑ ^a ^b ^c ^d David R. Lide: CRC Handbook of Chemistry and Physics, 75th Edition . CRC Press, Boca Raton, FL, USA 1994, ISBN 978-0-8493-0475-0 , pp. 3-62 .
↑ E. Rossegger, V. Schenk, F. Wiesbrock: Review: Design Strategies for Functionalized poly (2-oxazoline) s and Derived material . In: Polymers . tape 5 , no. 3 , 2013, p. 956-1011 , doi : 10.3390 / polym5030956 .
↑ ^a ^b K. Schwetlick: Organikum: Organisch-Chemisches Grundpraktikum, 24th edition. Wiley-VCH, Weinheim 2015, ISBN 978-3-527-33968-6 , p. 670 .
↑ F. Kazemi, AR Massah, M. Javaherian: chemo selective and scalable preparation of alkyl toluenesulfonate under solvent-free conditions . In: Tetrahedron . tape 63 , no. 23 , 2007, p. 5083-5087 , doi : 10.1016 / j.tet.2007.03.083 .
↑ AA Padmapriya, G. Just, NG Lewis: A new method for the esterification of sulfonic acids . In: Synth. Commun. tape 15 , no. 12 , 1985, pp. 1057-1062 , doi : 10.1080 / 00397918508076842 .
↑ BM Choudary, NS Chowdari, ML Kantam: Montmorillonite Clay Catalyzed Tosylation of Alcohols and Selective Monotosylation of Diols with p-Toluenesulfonic Acid: An Enviro-Economic Route . In: Tetrahedron . tape 56 , no. 37 , 2000, pp. 7291-7298 , doi : 10.1016 / S0040-4020 (00) 00626-8 .
^ DH Saunders, RA Barford, P. Magidman, LT Olszewski: Preparation and properties of a sulfobenzyl silica cation exchanger for liquid chromatography . In: Anal. Chem. Band 46 , no. 7 , 1974, p. 834-838 , doi : 10.1021 / ac60343a042 .
↑ F. Mohanazadeh, H. Amini: Silica chloride mediated alkylation of electron-rich aromatics by benzyl or tert-butyl chloride . In: Bull. Korean Chem. Soc. tape 31 , 2010, p. 3038–3040 , doi : 10.5012 / bkcs.2010.31.10.3038 .
^ B. Das, VS Reddy, MR Reddy: An efficient and selective tosylation of alcohols with p-toluenesulfonic acid . In: Tetrahedron Lett. tape 45 , no. 36 , 2004, p. 6717-6719 , doi : 10.1016 / tetlet.2004.07.076 .
↑ A. Kleemann, J. Engel: Pharmaceutical Ingredients: Syntheses, Patents, Applications, 2. neubearb. u. exp. Ed. Thieme, Stuttgart, New York 1982, ISBN 3-13-558402-X , p. 14 .
↑ Experiment 8.1.1.3: Bis- (3-methylbenzthiazol-2) -heptamethinecyanine tetrafluoroborate. (PDF; 12.1 kB) In: uni-wuerzburg.de. University of Würzburg, accessed on June 4, 2016 .
↑ Patent US8722926B2 : Beta-ketocarbonylquat compounds and process for the preparation thereof. Registered on July 20, 2011 , published on May 13, 2014 , applicant: Wacker Chemie AG, inventor: C. Herzig. ‌
^ R. Hoogenboom: Poly (2-oxazoline) s: A polymer class with numerous potential applications . In: Angew. Chem. Band 48 , no. 43 , 2009, p. 7978-7994 , doi : 10.1002 / anie.200901607 .

[Sigma-1] ↑ ^a ^b ^c ^d ^e ^f data sheet methyl p-toluenesulfonate from Sigma-Aldrich , accessed on May 30, 2016 ( PDF ).

[TCI-2] Entry on Methyl p-Toluenesulfonate at TCI Europe, accessed on May 30, 2016.

[Alfa-3] ta sheet methyl p-toluenesulfonate, 98% from AlfaAesar, accessed on May 30, 2016 ( PDF )(JavaScript required) .

[CRC-4] David R. Lide: CRC Handbook of Chemistry and Physics, 75th Edition . CRC Press, Boca Raton, FL, USA 1994, ISBN 978-0-8493-0475-0 , pp. 3-62 .

[5] E. Rossegger, V. Schenk, F. Wiesbrock: Review: Design Strategies for Functionalized poly (2-oxazoline) s and Derived material . In: Polymers . tape 5 , no. 3 , 2013, p. 956-1011 , doi : 10.3390 / polym5030956 .

[Organikum-6] K. Schwetlick: Organikum: Organisch-Chemisches Grundpraktikum, 24th edition. Wiley-VCH, Weinheim 2015, ISBN 978-3-527-33968-6 , p. 670 .

[7] F. Kazemi, AR Massah, M. Javaherian: chemo selective and scalable preparation of alkyl toluenesulfonate under solvent-free conditions . In: Tetrahedron . tape 63 , no. 23 , 2007, p. 5083-5087 , doi : 10.1016 / j.tet.2007.03.083 .

[8] AA Padmapriya, G. Just, NG Lewis: A new method for the esterification of sulfonic acids . In: Synth. Commun. tape 15 , no. 12 , 1985, pp. 1057-1062 , doi : 10.1080 / 00397918508076842 .

[9] BM Choudary, NS Chowdari, ML Kantam: Montmorillonite Clay Catalyzed Tosylation of Alcohols and Selective Monotosylation of Diols with p-Toluenesulfonic Acid: An Enviro-Economic Route . In: Tetrahedron . tape 56 , no. 37 , 2000, pp. 7291-7298 , doi : 10.1016 / S0040-4020 (00) 00626-8 .

[10] DH Saunders, RA Barford, P. Magidman, LT Olszewski: Preparation and properties of a sulfobenzyl silica cation exchanger for liquid chromatography . In: Anal. Chem. Band 46 , no. 7 , 1974, p. 834-838 , doi : 10.1021 / ac60343a042 .

[11] F. Mohanazadeh, H. Amini: Silica chloride mediated alkylation of electron-rich aromatics by benzyl or tert-butyl chloride . In: Bull. Korean Chem. Soc. tape 31 , 2010, p. 3038–3040 , doi : 10.5012 / bkcs.2010.31.10.3038 .

[12] B. Das, VS Reddy, MR Reddy: An efficient and selective tosylation of alcohols with p-toluenesulfonic acid . In: Tetrahedron Lett. tape 45 , no. 36 , 2004, p. 6717-6719 , doi : 10.1016 / tetlet.2004.07.076 .

[13] A. Kleemann, J. Engel: Pharmaceutical Ingredients: Syntheses, Patents, Applications, 2. neubearb. u. exp. Ed. Thieme, Stuttgart, New York 1982, ISBN 3-13-558402-X , p. 14 .

[14] Experiment 8.1.1.3: Bis- (3-methylbenzthiazol-2) -heptamethinecyanine tetrafluoroborate. (PDF; 12.1 kB) In: uni-wuerzburg.de. University of Würzburg, accessed on June 4, 2016 .

[15] Patent US8722926B2 : Beta-ketocarbonylquat compounds and process for the preparation thereof. Registered on July 20, 2011 , published on May 13, 2014 , applicant: Wacker Chemie AG, inventor: C. Herzig. ‌

[16] R. Hoogenboom: Poly (2-oxazoline) s: A polymer class with numerous potential applications . In: Angew. Chem. Band 48 , no. 43 , 2009, p. 7978-7994 , doi : 10.1002 / anie.200901607 .