Toluene → 1,1-Dimethylethyl 2-[4-(3-methyl-1,2,4-oxadiazol-5-yl)phenyl]-4,5,7,8-tetrahydropyrazolo[3,4-d]azepine-6(2H)-carboxylate

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Reaction Steps

To a suspension of 4-[6-{[(1,1-dimethylethyl)oxy]carbonyl}-5,6,7,8-tetrahydropyrazolo[3,4-d]azepin-2(4H)-yl]benzoic acid (may be prepared as described in Description 23) (185 mg, 0.52 mmol) in dichloromethane (10 ml) was added 1,1′-(oxomethanediyl)bis-1H-imidazole (168 mg, 1.04 mmol) and the reaction stirred at room temperature, under argon, overnight. The solvent was evaporated in vacuo. Toluene (5 ml) and then (1Z)-N-hydroxyethanimidamide (may be prepared as described in Description 30) (116 mg, 1.56 mmol) were added and the reaction mixture heated, under argon, at reflux overnight. A further 2 eq. of 1,1′-(oxomethanediyl)bis-1H-imidazole was added and stirring continued for a further 40 minutes. A further 3 eq. of (1Z)-N-hydroxyethanimidamide was added and stirring continued for a further 3 hours. The reaction was cooled to room temperature and the solvent evaporated in vacuo. The resulting crude mixture was diluted with dichloromethane and water, and extracted into dichloromethane (×2). The combined organic fractions were washed with water (×1), dried over magnesium sulphate and solvent evaporated in vacuo to afford the title compound (D34). MS (ES+) m/e 340 [M-tBu]+.

Provenance & Evidence