tert-butyl 5,7-dioxo-2,8-diazaspiro[3.5]nonane-2-carboxylate

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

Procedure: 7,9-Dioxo-2,6-diaza-spiro[3.5]nonane-2,8-dicarboxylic acid 2-tert-butyl ester 8-methyl ester (Example 156g)(8.3 g; 26.6 mmol) is dissolved in acetonitrile/water (170 ml; 9/1) and refluxed for 1 hour. The reaction mixture is evaporated to dryness and delivers the title compound as white crystals (6.35 g; 94%). refluxed for 1 hour The reaction mixture is evaporated to dryness