Ethyl Acetate → HCID 135730621, compound

Participants

Reaction Steps

Titanium trichloride (20.93 g, 140 mL of a 15% solution in hydrochloric acid) was added to a solution of 3-bromo-5-(2-ethoxy-5-nitropyridin-3-yl)-2-methyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one (Example 53) (7.66 g, 19.4 mmol) in acetic acid (100 mL). After 2 h the acetic acid was evaporated and azeotroped with toluene. The residue was partitioned between sodium bicarbonate solution and dichloromethane and the titanium salts filtered to aid separation of the aqueous and organic phases. The aqueous layer was saturated with sodium chloride and re-extracted with dichloromethane. The organics were dried (MgSO4) and concentrated to give a solid. Trituration with ethyl acetate gave 3 g of pure product.

Provenance & Evidence