The Synthetic Routes of Isradipine

Isradipine is a pharmaceutical compound that is used to treat hypertension and angina pectoris.
It is a calcium channel blocker, which means that it works by relaxing the smooth muscle in the walls of blood vessels, allowing them to widen and permit more blood to flow.
This, in turn, reduces the pressure on the blood vessels and helps to alleviate the symptoms of hypertension and angina.

There are several synthetic routes that can be used to produce isradipine, each with its own advantages and disadvantages.
The most commonly used route is the synthesis of isradipine via the synthesis of the amine precursor, 1,4-dihydro-2,6-dimethyl-4-oxo-5-oxazolidinone (DIDMO), followed by the cyclization of DIDMO to form the pyridyloxy moiety of isradipine.

The synthesis of DIDMO can be accomplished through several different methods, including the hydrogenation of 2,4-dimethyl-5-nitro-3-oxazolidinone, the reduction of 2,4-dimethyl-5-nitro-1,4-dihydro-3-oxazepine, and the condensation of 2-fluoro-3-nitro-1,3-oxazolidine with 1,4-diaminocyclohexane.

Once the DIDMO has been synthesized, it can be cyclized to form the pyridyloxy moiety of isradipine.
This can be accomplished through a process known as the "Kolbe-Schmitt" reaction, which involves the condensation of DIDMO with sodium hydroxide in the presence of a solvent such as benzene or toluene.
The resulting product is then treated with hydrochloric acid to obtain the isomeric form of isradipine.

Another synthesis route for isradipine is through the synthesis of the amino acid, L-proline, followed by the condensation of L-proline with chloromethyl methyl ether to form the methyl ester, which is then nitrated to form the nitrate ester.
The nitrate ester is then treated with a base, such as sodium hydroxide, to form the sodium salt, which is then hydrolyzed to form isradipine.

Yet another synthesis route for isradipine involves the synthesis of the amide, N-(2-hydroxyethyl)-N'-[(1,3-oxazolidin-2-yl)methyl]urea, followed by the treatment of the amide with hydrochloric acid to form isradipine.

No matter which synthesis route is used, the resulting product must be purified and transformed into the corresponding hydrochloride salt, which is the most common form of isradipine used in pharmaceutical applications.

In conclusion, isradipine can be synthesized through several different routes, each with its own advantages and disadvantages.
The most commonly used route is the synthesis of the amine precursor, 1,4-dihydro-2,6-dimethyl-4-oxo-5-oxazolidinone (DIDMO), followed by the cyclization of DIDMO to form the pyridyloxy moiety of isradipine.
Other routes include the synthesis of the amino acid L-proline, followed by the condensation of L-proline with chloromethyl methyl ether, and the synthesis of the amide N-(2-hydroxyethyl)-N'-[(1,3-oxazolidin-2-yl)methyl]urea, followed by the treatment of the amide with hydrochloric acid.
Regardless of the route used, the resulting product must be purified and transformed into the corresponding