Hydrazine hydrate (1:1) → HCID 11757210, compound

Participants

Reaction Conditions

Reaction Steps

1.78 g (3.4 mmol) of ester 32 were dissolved in 30 ml of MeOH. 0.83 ml of hydrazine hydrate was added and the mixture was stirred at 40° C. for 5 h. After that, a further 1.6 ml of hydrazine hydrate were added and the mixture was stirred at RT for 15 h. The solvents were removed i.v. and the residue was taken up in 80 ml of dichloromethane. 3.2 ml of a 20% solution of phosgene in toluene were added and the mixture was stirred for 3 days. After that, the solvent was removed i.v. and the residue was partitioned between 80 ml of water and 80 ml of ethyl acetate. When this was done, a solid precipitated out and was filtered off with suction. The organic phase was evaporated and the residue was combined with the solid and chromatographed on silica gel using heptane/ethyl acetate 1:5. 390 mg (21%) of the oxadiazolone 33 were obtained. Empirical formula C29H25N9O3; M.W.=547.58; MS (M+H) 548.2.

Provenance & Evidence