5,6-dimethyl-2-benzofuran-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:

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 solution of 4,5-dimethylphthalic anhydride (1.5 g, 8.5 mmol) in anhydrous tetrahydrofuran (25 ml) was added a 1.0 mol/L solution of tri-tert-butoxy aluminohydride in anhydrous tetrahydrofuran (8.5 ml) under ice cooling and argon atmosphere, and stirred for 1 hr under ice cooling. To the reaction solution was added ice-cold water, and the insoluble materials was filtered off. The filtrate was concentrated under reduced pressure to give crude 5,6-dimethyl-3-hydroxyphthalide. To this was added methyl iodide (12 g, 85 mmol) and K2CO3 (9.4 g, 68 mmol), and heated under reflux in acetone solvent for 5 hrs. The reaction solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (chloroform) to give 0.64 g of methyl 4,5-dimethyl-2-formylbenzoate. To the reaction solution was added ice-cold water the insoluble materials was filtered off The filtrate was concentrated under reduced pressure

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

Procedure: 4,5-dimethylphthalic anhydride (2.0 g, 11 mmol) and 3-aminopyridine (1.0 g, 11 mmol) were heated under reflux in acetic acid (30 ml) for 1.5 hrs. After standing to cool, water was added thereto, the precipitated crystals were collected by filtration, washed with water, followed by drying to give 2.3 g of 5,6-dimethyl-2-(3-pyridyl)isoindolin-1,3-dione. to cool the precipitated crystals were collected by filtration washed with water by drying

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

Procedure: 4,5-dimethylphthalic anhydride (1.7 g, 9.6 mmol) and 4-fluoroaniline (1.1 g, 9.6 mmol) were stirred with heating in dimethylformamide at 150° C. for 1 hr. After cooling, water was added to the reaction mixture, and the precipitated crystals were collected by filtration, washed with water, and dried. The resulting crystals were purified by silica gel chromatography (chloroform) to give 2.0 g of 5,6-dimethyl-2-(4-fluorophenyl)isoindolin-1,3-dione. After cooling the precipitated crystals were collected by filtration washed with water dried The resulting crystals were purified by silica gel chromatography (chloroform)

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

Procedure: To a solution of above-mentioned (a) (9.5 g, 53 mmol) in acetic acid (28 ml) was added dropwise a solution of bromine (6.1 ml, 0.12 mol) in acetic acid (28 ml) at 115° C. over a period of 45 minutes, and heated under reflux for 1 hr. The reaction solution was left overnight, and the precipitated crystals were collected by filtration, washed with diethyl ether, followed by drying to give 3.5 g of the title compound. heated under reflux for 1 hr the precipitated crystals were collected by filtration washed with diethyl ether by drying