The Synthetic Routes of 1,1′-[1,1′-Biphenyl]-4,4′-diylbis[2-bromoethanone]

The synthesis of 1,1′-[1,1′-Biphenyl]-4,4′-diylbis[2-bromoethanone], also known as BTB, is an important process in the chemical industry.
BTB is a versatile molecule with a wide range of applications, including as a building block for the synthesis of pharmaceuticals, agrochemicals, and other chemical products.

There are several synthetic routes to BTB, each with its own advantages and disadvantages.
In this article, we will explore some of the most commonly used synthetic routes to BTB and discuss their key features and applications.

Route 1: via 2-bromoethyl acetate

One of the most common synthetic routes to BTB involves the reaction of 4-bromoacetophenone with 1,1′-biphenyl thiol in the presence of a Lewis acid catalyst, such as aluminum chloride.
This reaction leads to the formation of 4-bromo-1,1′-biphenyl-2-carboxaldehyde, which can be further converted to BTB through a series of steps, including reduction, bromination, and dehydration.

The advantages of this route include its simplicity and the availability of the starting materials.
However, the reaction requires the use of a Lewis acid catalyst, which can be expensive and difficult to handle.

Route 2: via 2-bromoethanol

Another common route to BTB involves the reaction of 1,1′-biphenyl thiol with 2-bromoethanol in the presence of a solvent, such as ether or THF.
The reaction leads to the formation of 1,1′-biphenyl-2-diol, which can be converted to BTB through a series of steps, including reduction and dehydration.

The advantages of this route include the mild reaction conditions and the availability of the starting material.
However, the reaction requires the use of a solvent, which can increase the cost and complexity of the process.

Route 3: via 4-bromoacetophenone

Another synthetic route to BTB involves the reaction of 1,1′-biphenyl thiol with 4-bromoacetophenone in the presence of a base, such as pyridine or trimethylamine.
This reaction leads to the formation of 4-bromo-1,1′-biphenyl-2-carboxaldehyde, which can be further converted to BTB through a series of steps, including reduction, bromination, and dehydration.

The advantages of this route include the use of a mild base, which can make the reaction more efficient.
However, the reaction requires the use of a starting material that is more expensive and less readily available than 4-bromoacetophenone.

Overall, the synthetic routes to BTB involve a series of steps that require the use of various reagents, solvents, and catalysts.
The choice of route will depend on the availability and cost of the starting materials, as well as the desired yield and purity of the product.