1,1'-Carbonyldiimidazole → HCID 59527753, compound

Participants

Reaction Conditions

Reaction Steps

Under inert conditions a 100 mL four necked flask with a magnetic stirrer bar was charged with 0.89 g (5.5 mmol) of CDI in 10 mL MeCN. At 0-5° C. a solution of 0.99 g (5.5 mmol) 1-(4-fluorophenyl)piperazine in 10 mL MeCN was added drop wise during 15 min. The light yellow solution was stirred for 15 min at 0-5° C. and 3 h at 20° C. After 90 min an additional 70 mg CDI was added. 1.2 g (4.8 mmol) 4-(4-fluoro-phenyl)-piperidine-4-carboxylic acid ethyl ester (WO2000071517) in 5 ml MeCN was added. The mixture was heated for in total 5 days to reflux. The reaction mixture was concentrated under vacuum. The residue was dissolved in 15 ml N,N-dimethylacetamide and heated twice for 30 min at 200° C. under micro wave irradiations. The dark brown reaction solution was concentrated under high vacuum. The residue was taken up between 100 mL water and 100 mL ethyl acetate and extracted. The aqueous layers were extracted once with 100 mL ethyl acetate and the organic layers were washed once with 100 mL brine, dried over Na2SO4, filtered off, concentrated under vacuum and purified through column chromatography over silica eluting with a gradient formed from i-propanol and heptane. The product containing fractions were evaporated to yield 0.65 g (29%) of the title compound as light yellow viscous oil. MS ISP (m/e): 458.3 [(M+H)+].

Provenance & Evidence