A concise synthesis of quinazolinone TGF-β RI inhibitor through one-pot three-component Suzuki–Miyaura/etherification and imidate–amide rearrangement reactions

A simple and efficient synthesis of dihydropyrrolopyrazole boronic acid intermediate (5) has been developed. Utilization of a three-component Suzuki–Miyaura/etherification with microwave heating led to advanced compound 11 in high yield and with easy purification. Reaction of compound 11 with methanesulfonyl chloride at room temperature furnished the 1,3 O–N rearranged product (12), which is postulated to proceed via an intramolecular mechanism. The outlined synthesis provides a highly efficient and high-yielding route that is amenable to rapid analog synthesis.