Reaktion #1101268

Reaktionsgleichung

1,1,3,3-tetramethylisoindoline

N-benzylpthalimide

benzyl bromide

potassium phthalimide

→

N-benzyl-1,1,3,3-tetramethylisoindoline

Ausbeute 37.0%

Lösungsmittel

toluene

ethyl ether

methyl iodide

magnesium

Reaktionsbedingungen

Vorschrift

The synthesis set up by Rizzardo and coworkers is of the greatest practical interest, and comprises the synthesis of N-benzylpthalimide from benzyl bromide and potassium phthalimide, followed by its alkylation with a Grignard reagent. In the synthesis of 1,1,3,3-tetramethylisoindoline, for example, the Grignard reagent was prepared starting from methyl iodide and magnesium using, as solvents, ethyl ether and toluene (in succession): after 4 hours at reflux, N-benzyl-1,1,3,3-tetramethylisoindoline is obtained (37% yield), which is then treated with hydrogen (4 atmospheres; room temperature) in glacial acetic acid and in the presence of palladium-based catalysts (5% on coal). After 3 hours of reaction, 1,1,3,3-tetramethylisoindoline is obtained (II, R═CH3) with a yield of 96% (P. G. Griffiths, G. Moad, E. Rizzardo, D. H. Solomon, “Australian Journal of Chemistry” 1983, 36, 397).

Quelle