The Production Process of ETHYL 6-(TERT-BUTYL)-3-CYANO-2-HYDROXYISONICOTINATE

The production process of ethyl 6-(tert-butyl)-3-cyano-2-hydroxyisonicotinate, also known as ETBOH, is a multi-step process that involves several chemical reactions and purification steps.
The following is a detailed overview of the production process of ETBOH.

Step 1: Preparation of starting materials
The production of ETBOH starts with the preparation of the starting materials required for the reaction.
These materials include 6-tert-butyl-2,3-dihydro-1H-pyrrole-1-carboxylic acid, which is also known as 6-tert-butyl-2,3-dioxopropionic acid, and sodium hydroxide.
The 6-tert-butyl-2,3-dihydro-1H-pyrrole-1-carboxylic acid can be synthesized using various methods known in the art, such as the reaction of 6-bromo-2,3-dihydro-1H-pyrrole-1-carboxylic acid with tert-butyl alcohol in the presence of a Lewis acid catalyst, such as aluminum chloride.
Sodium hydroxide is typically obtained by the neutralisation of sodium hydroxide solution with a mineral acid, such as hydrochloric acid or sulfuric acid.

Step 2: Esters formation
The next step in the production of ETBOH is the formation of the ester between 6-tert-butyl-2,3-dihydro-1H-pyrrole-1-carboxylic acid and ethyl alcohol.
This reaction is typically carried out in the presence of a strong acid catalyst, such as sulfuric acid or phosphoric acid.
The reaction can be carried out in a solvent, such as water or an organic solvent, such as acetone or ethyl acetate.
The use of a solvent allows for better mixing of the reaction components and facilitates the removal of the formed ester.

Step 3: Nitration
The ester obtained from step 2 is then subjected to a nitration reaction to introduce the nitro group (-NO2) into the molecule.
This reaction can be carried out using various nitrating agents such as nitric acid, hydrogen nitrate, or nitrosonium salt.
The reaction is typically carried out in the presence of a solvent, such as water or an organic solvent, and at a temperature between 0°C and 100°C.
The use of a solvent helps to facilitate the removal of the formed byproducts and helps to maintain a consistent reaction temperature.

Step 4: Reduction
After the nitration reaction, the next step is to reduce the nitro group to introduce the hydroxyl (-OH) group into the molecule.
This can be done using various reducing agents such as lithium aluminum hydride (LiAlH4), hydrogen gas, or sodium borohydride.
The reduction reaction is typically carried out in the presence of a solvent, such as water or an organic solvent, and at a temperature between 0°C and 100°C.
The use of a solvent helps to facilitate the removal of the formed byproducts and helps to maintain a consistent reaction temperature.

Step 5: Deprotection
The final step in the production of ETBOH is the deprotection of the molecule to remove the 2,3-dihydro-1H-pyrrole-1-carboxylic acid group.
This can be done using various deprotection agents such as hydrochloric acid or sodium hydroxide.
The deprotection reaction is typically carried out in the presence of a solvent, such as water or an organic solvent, and at a temperature between 0°C and 100°C.
The use of a solvent helps to