HCID 20461683, compound → HCID 20461671, compound

Participants

Reaction Steps

A mixture of 1,1-difluoro-2-phthalimido-4-methylene-5-bromo-pentane (impure, evaluated 67 mmoles) prepared as in Step C above, and potassium phthalimide (13.9 g, 75 mmoles) is heated at 75° C. in dry N,N-dimethylformamide (DMF) (100 mL) for 3 hours. After removal of the DMF under vacuum, the residue is dissolved in chloroform and extracted with 1 N potassium hydroxide and three times with water. Work-up as described in Example 1(D) affords a colored oil (30 g, containing solvents) which is chromatographed on silica gel (petroleum ether/ether acetate: 70/30). The oil obtained (11.3 g) is crystallized from chloroform/ether/petroleum ether to give 1,1-difluoro-2,5-diphthalimido-4-methylene-pentane slightly contaminated (about 15%) by 1,1-difluoro-2,5-diphthalimido-4-methyl-3-pentene (7.9 g of mixture, yield based on 1,1-difluoro-2-phthalimido-4-methyl-4-pentene: 29%).

Provenance & Evidence