Phthalimide → 2-[4-(1-Diphenylmethylpiperidin-4-yl)-butyl]-isoindol-1,3-dione

Participants

Reaction Conditions

Reaction Steps

135.0 g (417. mmol) 4-(1-diphenylmethyl-piperidin-4-yl)-butan-1-ol, 109.5 g (417 mmol) triphenylphosphine and 61.3 g (417 mmol) phthalimide are suspended in THF. Thereafter, 2.6 g (417 mmol) azodicarboxylic acid diethyl ester are added dropwise within two and a half hours under protective atmosphere and light cooling (ca. 15-25° C.). After an additional hour, the solvent is removed under vacuum and the residue is crystallized three times from acetic acid ethyl ester (1000 ml, 1200 ml and 1100 ml). Colorless crystals with an MP of 150-152° C.; yield 103 g (54.5 %).

Provenance & Evidence