Methyl bisulfate is a chemical compound with the molecular formula CH
4O
4S. This compound is the mono-
methyl ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides a ...
of
sulfuric acid. The significance of methyl bisulfate is that it is an intermediate in the hydrolysis of the important reagent
dimethyl sulfate, (CH
3)
2SO
4:
:(CH
3)
2SO
4 + H
2O → (CH
3)HSO
4 + CH
3OH
Methyl bisulfate is a strong acid:
:(CH
3)HSO
4 → (CH
3)SO
4− + H
+
Methyl bisulfate came into the public view in 1993 with the discovery that certain mercury compounds catalyze the
conversion
Conversion or convert may refer to:
Arts, entertainment, and media
* "Conversion" (''Doctor Who'' audio), an episode of the audio drama ''Cyberman''
* "Conversion" (''Stargate Atlantis''), an episode of the television series
* "The Conversion" ...
of methane to methylbisulfate in good yields with excellent selectivity in concentrated sulfuric acid. However, because of the toxicity and concerns with the use of mercury it wasn't until 1998 when platinum complexes were found that catalyze the reaction of
CH4 by SO
3 and O
2 that it came into the limelight:
:CH
4 + SO
3 +
1/
2 O
2 → (CH
3)HSO
4
This discovery pointed to a possible method for upgrading inexpensive and abundantly available methane (
natural gas
Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbo ...
) into
methanol, which is both a more useful chemical and more easily shipped than methane. The process is proposed to proceed via an intermediate containing the Pt-CH
3 group.
Methyl bisulfate's
conjugate base
A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid donates a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a ...
is used as a
counterion in the
formulation of some pharmaceutical drugs, where it is typically referred to as metilsulfate.
References
{{reflist
Methyl esters
Sulfate esters