2-benzyl-4H-isoquinoline-1,3-dione

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a well-stirred ice-bath-chilled solution of 2-benzyl-4H-isoquinoline-1,3-dione (5.0 g, 20 mmol) in methanol (40 ml), sodium borohydride (3.0 g, 80 mmol) was added portionwise over 20 minutes. The reaction mixture was stirred at ambient temperature for 48 hours. TLC inspection of a reaction aliquot confirmed substantial formation of product, with some starting material remaining. TLC Rf of the title compound (silica gel plates; u.v. detection; elution with ethyl acetate/hexane=3.7 in volume): 0.24. The ice-bath-chilled reaction mixture was cautiously quenched with water (3 ml). Anhydrous sodium sulfate was added to dry the mixture, which was then filtered. The filtrate was concentrated in vacuo to a dark green oil (3.5 g). Flash chromatography (silica gel, 40 micron mesh; elution with ethyl acetate hexane=3.7 volume) afforded the title compound as a colorless amorphous solid (1.35 g). The labile material was used immediately in the next step. was added portionwise over 20 minutes TLC inspection of a reaction aliquot confirmed substantial formation of product

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture consisting of homophthalic acid (25 g, 0.139 mol) and benzylamine (15.2 ml, 14.91 g, 0.139 mol) was heated at 165°-180° C. for two hours, producing a vigorous release of water vapor. Cooling afforded a hard green solid which was pulverized, triturated with diethyl ether, and isolated by filtration to afford the title compound as a light-green granular solid (29.4 g) used in the next step without further purification. was heated at 165°-180° C. for two hours Cooling afforded a hard green solid which triturated with diethyl ether isolated by filtration