Sulfuric acid mono-methyl ester

Sulfuric acid can form ester derivatives with alcohols, though since it is a dibasic acid (pAla — 3, 2) it can form both mono- and di-esters. Thus, acid-catalysed reaction of methanol with sulfuric acid gives initially methyl hydrogen sulfate, and with a second mole of alcohol the diester dimethyl sulfate. Though not shown here, the mechanism will be analogous to the acid-catalysed formation of carboxylic acid esters (see Section 7.9). 

A number of enzymes known as sulfuric ester hydrolases (EC 3.1.6) are able to hydrolyze sulfuric acid esters. They comprise arylsulfatase (sulfatase, EC 3.1.6.1), steryl-sulfatase (steroid sulfatase, steryl-sulfate sulfohydrolase, arylsulfatase C, EC 3.1.6.2), choline-sulfatase (choline-sulfate sulfohydrolase, EC 3.1.6.6), and monomethyl-sulfatase (EC 3.1.6.16). Whereas mono-methyl-sulfatase is highly specific and does not act on higher homologues, arylsulfatase has a broad substrate specificity and is of particular significance in the hydrolysis of sulfate conjugates of phenols, be they endogenous compounds, drugs, or their metabolites [167-169],... 

Sulfuric or phosphoricacids are used for the ketonic hydrolysis, as in the preparation of methyl n-amyl ketone. Also, the hydrolysis is brought about by boiling with acetic-sulfuric acid mixture, hot 5% potassium hydroxide solution, or hydriodic acid if the hydrolysis is especially difficult. Benzyl ace tone, QH, CHjCHjCOCH, is formed by hydrolysis of the corresponding /8-keto ester with water at 150-250° and 200 atm. Diaikylated /S-keto esters are stable to this treatment therefore, a single ketone can be obtained from a mixture of mono- and di-alkylated /3-keto esters. ... 

The synthesis of fatty acid amide ethoxyiates can be described in three steps (see Scheme 1). The first step concerns the preparation of fatty acid methyl esters. The fatty acid is heated in sulfuric acid in the presence of methanol. The lower phase of the resulting two-phase system then contains the fatty acid methyl ester. Second, the fatty acid methyl ester is reacted with mono-... 

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