1,8-DIAZA-SPIRO[4.5]DECANE-1-CARBOXYLIC ACID TERT-BUTYL ESTER synthesis

Yield:-

Reaction Conditions:

with hydrogen;palladium on activated charcoal in methanol;toluene at 90; under 53203.6 Torr;

Steps:

tert-Butyl l,8-diazaspiro[^"4.5]decane-l-carboxylate (A-8^"); Crude A-7 (200 g, 607 mmol) was dissolved in 600 mL MeOH in a IL autoclave where 2O g of Pd/C as a toluene phase was added. The autoclave was sealed and charged with 70 atm of H2 and heated at 90⁰C until the required amount of H2 was consumed. The solution was filtered throughCelite and the MeOH was removed to provide crude material that was distilled to yield A-8 as a colorless oil that solidified upon standing; 98-103⁰C at 0.25 mbar. Data for AJ5: IHNMR (500 MHz, CDCI3): δ EPO 3.5 - 3.4 (m, 2H), 3.1 (m, 2H), 2.6 (m, 3H), 2.4 (bs, IH), 2.15 (bs, IH), 1.9 (m, 2H), 1.7 (m, 2H), 1.6 ? 1.3 (m, HH) ppm; HRMS m/z (M+H) 241.1912 found; 241.1940 required.

References:

WO2007/25069,2007,A2 Location in patent:Page/Page column 27; 29-30