The Synthetic Routes of Ethyl 7-isoquinolinecarboxylate

Ethyl 7-isoquinolinecarboxylate is an important intermediate in the synthesis of various chemicals, pharmaceuticals, and agrochemicals.
The demand for this compound has been increasing steadily in recent years, which has prompted the development of new and efficient synthetic routes.
In this article, we will discuss some of the popular synthetic routes for the synthesis of ethyl 7-isoquinolinecarboxylate.

1. The classical route: The classical route for the synthesis of ethyl 7-isoquinolinecarboxylate involves the reaction of 7-bromo-1,4-benzoxazepine with ethyl isocyanate in the presence of a polar solvent, such as DMF or DMSO.
   The reaction is exothermic, and any excess of reagents should be avoided to prevent unwanted reactions.
   The product can be isolated by filtering the reaction mixture and performing a simple extraction with a suitable solvent, such as ethyl acetate.
   
2. The microwave-assisted route: This route involves the use of microwave irradiation to accelerate the reaction.
   The reaction is performed in a sealed reaction vessel, and the reaction mixture is irradiated with microwaves for a specified time.
   The use of microwave irradiation results in a shorter reaction time and a higher yield of the desired product.
   
3. The one-pot route: The one-pot route involves the synthesis of ethyl 7-isoquinolinecarboxylate and 7-bromo-1,4-benzoxazepine in a single step using a suitable reagent, such as sodium hydride.
   The reaction is performed in a polar solvent, such as DMF or DMSO, and the product can be isolated by filtering the reaction mixture.
   
4. The green route: The green route involves the use of eco-friendly reagents and solvents to minimize the environmental impact of the synthesis.
   This route involves the reaction of 7-bromo-1,4-benzoxazepine with ethyl isocyanate in the presence of a base, such as potassium carbonate, and a polar solvent, such as N,N-dimethylacetamide.
   The reaction is followed by simple extraction with a suitable solvent, such as ethyl acetate, to isolate the product.
   
5. The hydrothermal route: The hydrothermal route involves the synthesis of ethyl 7-isoquinolinecarboxylate under hydrothermic conditions, such as high temperature and pressure.
   The reaction is performed in a suitable solvent, such as water or a polar organic solvent, and the product can be isolated by filtering the reaction mixture.
   
6. The photochemical route: The photochemical route involves the use of light to accelerate the reaction.
   The reaction is performed in a suitable solvent, such as ethanol or acetonitrile, and the product can be isolated by filtering the reaction mixture.
   

In conclusion, there are several synthetic routes for the synthesis of ethyl 7-isoquinolinecarboxylate, and the choice of route depends on various factors, such as the availability of reagents, the reaction conditions, and the desired yield.
The classical route and the microwave-assisted route are the most popular routes, but the green and hydrothermal routes are increasing in popularity due to their eco-friendly nature.
The one-pot route and the photochemical route are less commonly used but provide a convenient and efficient synthesis of the desired product.