Mesyl, abbreviation

Abbreviations for methanesulfonyl chloride and /7-toluenesulfonyl chloride are mesyl chloride and tosyl chloride , respectively. 

Section 7.8). Other classes of derivatives are thus most conveniently prepared from the sulfonyl chloride. Reaction with an alcohol leads to formation of a sulfonate ester. Two common sulfonyl chloride reagents employed to make sulfonate esters from alcohols arep-toluenesulfonyl chloride, known as tosyl chloride, and methanesulfonyl chloride, known as mesyl chloride (see Section 6.1.4). Note the nomenclature tosyl and mesyl for these groups, which may be abbreviated to Ts and Ms respectively. 

The most frequently encountered representative of the KSOsO" close of leaving groups is probably the toluene-p-eulfonote anion (commonly abbreviated to toeylate ), but others are occasionally employed aa well. The latter include the methylaulfonatc ( mesylate ) end the p-bromobenzenesulfbaate ( brosylate ) ankme. 

Abbreviations are often used for monovalent groups that commonly appear in organic compounds. Some of these abbreviations are shown in Table 1.1. Aryl may be phenyl, a substituted phenyl, or a heteroaromatic group like furyl, pyridyl, or pyrrolyl. Tosyl is shorthand for p-toluenesulfonyl, mesyl is shorthand for methanesul louyi, and triflyl is shorthand for trifluoromethanesulfonvl. TsO, MsO-, and TI O are abbreviations for the common leaving groups tosylate, mesylate, and triflate, respectively. 

Such an acid is 4-methylbenzenesulfonic acid (51 commonly known as p-tol-uenesulfonic acid, tosic acid, or p-TsOH this benzene nomenclature system is discussed in Chapter 21, Section 21.2). Another commercially available sulfonic acid is methanesulfonic acid (52), commonly abbreviated as MsOH, where Ms = mesyl. Tosic acid is a crystalline sohd that is cheap, readily available, and soluble in most organic solvents. Throughout most of this book, the acid catalyst is simply referred to as H+, but the actual acid is usually sulfuric acid or tosic acid. 

Two of the most commonly used sulfonyl chlorides are p-toluenesulfonyl chloride (abbreviated tosyl chloride, TsCl) and methanesulfonyl chloride (abbreviated mesyl chloride, MsCl). Treating ethanol with p-toluenesulfonyl chloride in the presence of pyridine gives ethyl p-toluenesulfonate (ethyl tosylate). Pyridine is added to catalyze the reaction and to neutralize the HCl formed as a by-producf. Cyclohexanol is converted to cyclohexyl methanesulfonate (cyclohexyl mesylate) by a similar reaction of cyclohexanol with methanesulfonyl chloride. 

---