Phosphorus oxide (P4O10) → HCID 86613800, compound

Participants

Reaction Conditions

Reaction Steps

Add slowly cold (ice bath) absolute EtOH (1.7 mL) to a cooled 0° C. stirred mixture of (+/−)-cis-4-[(3,5-bis-trifluoromethyl-benzyl)-(3-oxo-butyryl)-amino]-2-ethyl-6-trifluoromethyl-3,4-dihydro-2H-[1,5]naphthyridine-1-carboxylic acid isopropyl ester (221 mg, 0.34 mmol) and phosphorus pentoxide (880 mg, 6.2 mmol). Add hydrazine hydrate (0.105 mL, 3.4 mmol) while keeping the mixture cooled at 0° C. Seal the tube and heat the reaction mixture at 100° C. overnight. Cool down the mixture and remove the solvents under reduced pressure. Partition the residue between water and dichloromethane. Separate the layers and dry the organic phase, filter, and concentrate in vacuo. Purify the residue by silica gel flash chromatography, eluting with hexanes/ethyl acetate, to afford the title compound (82 mg, 38%). MS (ES+): 638 (M+H).

Provenance & Evidence