Synthesis and reactivity of pyrrolo(3,2-d)(1,3)oxazine-2,4-dione. Access to new pyrrolo(3,2-e)(1,4)diazepine-2,5-diones

Abstract A convenient synthesis of pyrrolo[3,2- d ][1,3]oxazine-2,4-dione 4 is described and its reactivity towards various nucleophiles studied. The regioselective ring opening of anhydride 4 or its N -alkylated analog 25 in the presence of alanine or proline afforded, respectively, imidazolidinedione 22 and N -protected pyrrolo[3,2- e ][1,4]diazepines 30 and 31 in a one-pot process. In a last part of this study, an alternative route to produce a library of eight non protected pyrrolo[3,2- e ][1,4]diazepine-2,5-diones 35a – h is described to overcome the limited reactivity of anhydride 4 .