2,4,6-Triisopropylbenzenesulfonyl azide → 3-Azido-2,4-dioxo-1,5-bis-(cyclopropylmethyl)-2,3,4,5-tetrahydro-1H-1,5-benzodiazepine

Participants

Reaction Conditions

Reaction Steps

For this substrate General Procedure 8-K was modified in the following manner. Initially the product from Step A was suspended (not a solution) in THF at −78° C., and following addition of the KN(TMS)2 solution, this suspension was allowed to warm to −30° C., during which the suspension became a solution, and was re-cooled to −78° C. Upon re-cooling to −78° C. a precipitate began to form, therefore the reaction flask containing the mixture was partially raised above the cooling bath until the internal temperature rose to −50° C.; then the trisyl azide solution was added. The cooling bath was removed and the mixture allowed to warm to −20° C. whereupon the mixture had become a nearly homogenous solution, and the AcOH was added. Then, treated as described in the general procedure. 3-Azido-2,4-dioxo-1,5-bis-(cyclopropylmethyl)-2,3,4,5-tetrahydro-1H-1,5-benzodiazepine was purified by trituration with hot to room temperature EtOAc, followed by recrystalization from hot to −23° C. CHCl3/EtOAc/EtOH (5:5:1) and isolated as a white solid.

Provenance & Evidence