The Production Process of 3-chloro-7H-pyrrolo[2,3-c]pyridazine

The production process of 3-chloro-7H-pyrrolo[2,3-c]pyridazine is a complex multi-step process that involves various chemical reactions and purification steps.
The final product is a white to off-white powder with a characteristic odor, which is widely used as an intermediate in the production of various pharmaceuticals and agrochemicals.

Step 1: Synthesis of 2-[(4S)-4-(dichloromethyl)-2-oxo-1,3-oxazolidin-3-yl]-N-(4-bromo-2-oxo-1,3-oxazolidin-3-yl)acetamide
This step involves the synthesis of 2-[(4S)-4-(dichloromethyl)-2-oxo-1,3-oxazolidin-3-yl]-N-(4-bromo-2-oxo-1,3-oxazolidin-3-yl)acetamide, which is then further hydrolyzed to produce 3-chloro-7H-pyrrolo[2,3-c]pyridazine.

Step 2: Synthesis of 2-[(4S)-4-(dichloromethyl)-2-oxo-1,3-oxazolidin-3-yl]-N-(4-bromo-2-oxo-1,3-oxazolidin-3-yl)acetamide
In this step, 2-((4S)-4-(dichloromethyl)-2-oxo-1,3-oxazolidin-3-yl)-N-(4-bromo-2-oxo-1,3-oxazolidin-3-yl)acetamide is synthesized by reacting (4S)-4-(dichloromethyl)-2-oxo-1,3-oxazolidin-3-one with 4-bromo-2-oxo-1,3-oxazolidin-3-one in the presence of a catalytic amount of a strong acid, such as sulfuric acid or phosphoric acid.

Step 3: Hydrolysis of 2-[(4S)-4-(dichloromethyl)-2-oxo-1,3-oxazolidin-3-yl]-N-(4-bromo-2-oxo-1,3-oxazolidin-3-yl)acetamide
After the synthesis of 2-[(4S)-4-(dichloromethyl)-2-oxo-1,3-oxazolidin-3-yl]-N-(4-bromo-2-oxo-1,3-oxazolidin-3-yl)acetamide, the product is hydrolyzed using a strong acid, such as hydrochloric acid or sulfuric acid.
This hydrolysis step results in the formation of 3-chloro-7H-pyrrolo[2,3-c]pyridazine.

Step 4: Purification of 3-chloro-7H-pyrrolo[2,3-c]pyridazine
After the hydrolysis step, the resulting product is purified using various purification techniques, such as crystallization, filtration, and chromatography.
This step is important to remove any impurities that may have been introduced during the synthesis and hydrolysis steps, and to obtain a pure sample of 3-chloro-7H-pyrrolo[2,3-c]pyridazine.

Overall, the production process of 3-chloro-7H-pyrrolo[2,3-c]pyridazine involves several multi-step synthesis and purification steps.
The yield and quality of the final product can be affected