4,7-diazaspiro[2.5]octane-5,8-dione

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 350 mg of compound 24 was suspended in 200 ml of dry tetrahydrofuran followed by the addition of 0.6 g of lithium aluminum hydride. The mixture was refluxed for 14 hours. To this reaction mixture was then added 0.6 g of water, 0.6 g of 15% aqueous sodium hydroxide and 1.8 g of water in the order mentioned under ice-cooling and the resulting precipitate was removed by filtration. The precipitate was thoroughly washed with tetrahydrofuran and ether and the washings and the filtrate were combined. The solvent was then removed under reduced pressure to give title compound 4,7-diazaspiro[2,5]octane 25 as a crude product. This product was subjected, without purification, to the substitution reaction. The mixture was refluxed for 14 hours cooling the resulting precipitate was removed by filtration The precipitate was thoroughly washed with tetrahydrofuran and ether The solvent was then removed under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1.04M Borane-tetrahydrofuran complex in tetrahydrofuran (24.7 mL) was added dropwise to 4,7-diazaspiro[2.5]octane-5,8-dione (1.2 g) in tetrahydrofuran (30 mL) at 0° C. over a period of 30 minutes, and the resultant mixture was refluxed under heat for 13 hours. To the reaction mixture, methanol (4 mL) and 4N HCl-dioxane (8 mL) were added at 0° C., and the mixture was refluxed under heat for 1 hour, and then cooled in air. The precipitated solid was recovered by filtration, and washed with tetrahydrofuran, to thereby give a product mixture containing the title compound (1.86 g). under heat for 13 hours the mixture was refluxed under heat for 1 hour cooled in air The precipitated solid was recovered by filtration washed with tetrahydrofuran to thereby give a product mixture