Ammonia → 2-Butyl-1,3-diaza-spiro[4.4]nonan-4-one

Participants

Reaction Conditions

Reaction Steps

Ammonia solution (20%; 20 g, 0.30 mol.) is added to a solution of 126 g of 1-aminocyclopentanecarboxamide (>98%, 0.98 mol.) in 150 g of water. 86 g of valeraldehyde (0.99 mol.) are then added at 15° C., during which the temperature rises to 32° C. The reaction mixture is heated to 70° C. and stirred for 7 hours at that temperature. 350 ml of MIBK are added to the emulsion, and the mixture is cooled, with stirring, and the organic phase is separated off. The extract is extensively concentrated by evaporation (200 g), and 200 g of n-hexane are added, and the crystals are filtered off. After drying there remain 125 g of 2-butyl-1,3-diaza-spiro [4.4]nonan4-one (HPLC: 98.6%).

Provenance & Evidence