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Chemicals - Applications |
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| Pharmaceuticals |
| Market Overview |
The pharmaceutical market, which Varsal serves, encompasses
the following areas: ethical drugs, topicals, and nutraceuticals.
Varsal provides chemicals for use as key intermediates or as processing
chemicals.
The key products/categories supplied to this market include methane
sulfonic acid (MSA), methane sulfonyl chloride (MSC), amino acids,
triflates and mesylate salts, sodium hypophosphite, and phosphorous
pentoxide. |
| Products/Applications |
| Why Varsal’s MSC and MSA are better |
Methanesulfonic acid (MSA) and methanesulfonyl chloride (MSC) are
most often used to make mesylate salts. When this is the application,
the quality is extremely important. Of particular concern are the
esters of MSA and MSC that can result from the formation of these
chemicals.
There are two synthesis routed used to make commercial quantities
of MSA and MSC. These are:
1) Methyl Mercaptan route
2) Dimethyl Disulfide route
The carcinogenic esters of MSA are formed at temperatures of about
162-166oC. When Methyl Mercaptan is used as the starting
material, MSA is only formed at a reaction temperature of 178-180oC,
which is higher than the temperature of formation of the esters. MSC,
on the other hand, is formed at the temperature of 125-128oC,
which is lower than the temperature of formation of the esters.
The methyl mercaptan route synthesizes MSA directly from the methyl
mercaptan, and requires the higher temperature that leads to the ester
formation. The Dimethyl Disulfide route, however, requires the synthesis
of MSC first, followed by hydrolysis of the MSC to MSA. This route
avoids the high temperatures that create the carcinogenic esters.
This is also a safer as well as cleaner route to make MSA.
Varsal tests for the ethyl, methyl esters of MSA as well as the Methyl
thiomethanesulfonate ester and can assure ester -free MSA and MSC
for mesylate salt synthesis. |
| Triflates and Mesylate salts for chiral synthesis |
Sulfonate esters are great leaving groups in organic syntheses,
and are often used as substrates in SN2 reactions for that
reason. Triflates, however, are the best leaving group of them all,
due to the stabilizing effect of the fluorine atoms on the anion.
These leaving groups are extremely useful in making a well-defined
stereochemical reaction pathway possible, especially for the conversion
of the hydroxyl group of alcohols. The stereochemical pathway resulting
form such a reaction is predictable, and therefore very important
for organic synthesis with reliable results, because the hydroxyl
activation is achieved without altering the absolute stereochemistry
of the Carbon bearing the Functional Group.
Besides using the sulfonate esters, phosphate esters can also be used
to activate the OH group for substitution. Varsal has several phosphorous
derivatives for this application, such as hypophosphorous acid and
phosphorous pentoxide.
MSA is easy to use as a liquid, so better than pTSA. It can be recovered
and re-used. MSA is also biodegradable.
Triflates are expensive, but are 4000-10,000 times more reactive than
mesylate or tosylate leaving groups. When combined with silanes, triflates
can be very useful for silylation of unreactive substrates, such as
primary and secondary alcohols. Varsal has a unique advantage in having
a very strong position with the triflates as well as with the Grignard
chemistry used to make silanes.
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| Amino Acids |
Amino Acids are natural chiral compounds. They therefore
make low-cost and useful starting materials for chiral synthesis.
They are also very important as building blocks for peptide/peptidomimetic
compounds. In addition to natural amino acids, Varsal offers beta
amino acids and alcohols for chiral synthesis.
As the building blocks for proteins, amino acids are an important
component in enteral nutrition, IV solutions, and infant formulas.
Varsal offers high purity grades, and tests for chiral purity and
other amino acids, as well as providing full traceability for production
processing and raw materials. Pyrogen free amino acids are also available.
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