Reaktion #45870

Reaktionsgleichung

dimethylamine

acetic acid

sodium cyanoborohydride

sodium hydrogencarbonate

2-Cyclopropyl-5-methyl-7-(3-oxocyclopentyl)-6-phenyl-1,3-benzoxazole-4-carbonitrile

→

ammonia methanol

2-cyclopropyl-7-[(1R*,3R*)-3-(dimethylamino)cyclopentyl]-5-methyl-6-phenyl-1,3-benzoxazole-4-carbonitrile

Ausbeute 41.5%

Lösungsmittel

methanol

chloroform

chloroform

Reaktionsbedingungen

Aufarbeitung

1. 1
   ExtraktionThe aqueous layer was extracted twice with chloroform
2. 2
   Waschenwashed with saturated brine
3. 3
   Trocknendried over anhydrous sodium sulfate
4. 4
   SonstigeThe insoluble matter was separated by filtration
5. 5
   Sonstigethe solvent was evaporated away
6. 6
   Sonstigethe resulting residue was purified by preparative TLC (eluent, chloroform

Vorschrift

2-Cyclopropyl-5-methyl-7-(3-oxocyclopentyl)-6-phenyl-1,3-benzoxazole-4-carbonitrile (I-303) (44 mg, 0.12 mmol) was dissolved in chloroform (1 ml) and methanol (1 ml), and at 0° C., dimethylamine (2 M tetrahydrofuran solution) (247 μl, 0.49 mmol), acetic acid (29 μl, 0.49 mmol) and sodium cyanoborohydride (33 mg, 0.49 mmol) were added. The solution was gradually warmed up to room temperature, then stirred for 21 hours, and fractionated with chloroform and an aqueous saturated sodium hydrogencarbonate solution. The aqueous layer was extracted twice with chloroform. The organic layers were combined, washed with saturated brine, and dried over anhydrous sodium sulfate. The insoluble matter was separated by filtration, the solvent was evaporated away and the resulting residue was purified by preparative TLC (eluent, chloroform:7 N ammonia/methanol solution=97:3, v/v) to obtain 2-cyclopropyl-7-[(1R*,3R*)-3-(dimethylamino)cyclopentyl]-5-methyl-6-phenyl-1,3-benzoxazole-4-carbonitrile (#141) (9.6 mg, 20%) as a white solid. Next, 2-cyclopropyl-7-[(1R*,3S*)-3-(dimethylamino)cyclopentyl]-5-methyl-6-phenyl-1,3-benzoxazole-4-carbonitrile (#142) (26 mg, 55%) was obtained as a white solid.

Quelle