Development of a Scalable and Safer Synthesis of Diazeniumdiolates

Although diazeniumdiolates (DAZDs) and the synthetic methods to access DAZDs were discovered over 50 years ago, the current methodology is not safe, has a limited substrate scope, and is not amenable to large-scale production. For example, a recent investigation utilizing the standard methodology to prepare DAZDs resulted in two unexpected explosions, highlighting the need for safer and more practical chemistry. Recently, we have reported a general, scalable, safer, and high-yielding methodology adaptable to large-scale synthesis of diazeniumdiolates in water using a calcium hydroxide base. Herein, we report the full account for the development of the reaction. The merit of this strategy is evidenced by the highly efficient and safer preparation of a key DAZD intermediate, on the kilogram scale, needed for the preparation of MK-8150 (1), a novel O-2-alkylated diazeniumdiolate NO donor under investigation as a potent and significant blood-pressure-lowering drug candidate.