Acetoacetic Acid → 2H-Indol-2-one, 3-(1,3-dihydro-3-oxo-2H-indol-2-ylidene)-1,3-dihydro-

To a solution of isatin analogs (77 mg, 0.425 mmol) in methanol (5 ml) were added 5-substituted indoxy N, O diacetate (100 mg, 0.425 mmol) and the mixture was stirred for 5 min. Anhydrous Na2CO3 (112.5 mg, 1.06 mmol) was added, and the stirring was continued for 3 h at room temperature. The dark precipitate was filtered and washed with cold water, and dried under reduced pressure to give derivatives of 5,5-substituted indirubin, 7-10. The appropriate indirubin derivative (10 mg, 0.032 mmol) was dissolved in pyridine (0.3 ml) and added hydroxylamine hydrochloride (6.6 mg, 0.095 mmol). The reaction mixture was heated under reflux at 120° C. for 2 h. After cooling, the product was acidified with 1N HCl. The precipitation was filtered and washed with water to afford quantitatively the corresponding 3′-oxime selectively in a (2′Z, 3′E) form. The product was purified by silica gel column chromatography (Chloroform:Methanol=20:1).

1. waitthe stirring was continued for 3 h at room temperature
2. filtrationThe dark precipitate was filtered
3. washwashed with cold water
4. customdried under reduced pressure

ORD record

ord-685f6a672c144f8a992cc1b3e1fe38dd

Source dataset

uspto-grants-2014_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08859783B2