Hydrazine → 4-amino-N-(cyclopentyloxy)-3-nitrobenzenesulfonamide

Participants

Reaction Steps

A solution of 2-(cyclopentyloxy)-1H-isoindole-1,3(2H)-dione (10.00 g, 43.30 mmol) in anhydrous tetrahydrofuran (100 mL) at ambient temperature under an Argon atmosphere was treated with anhydrous hydrazine (1.49 mL, 47.63 mmol). After stirring vigorously for 2.5 hours, the resulting slurry was filtered and washed with approximately 20 mL of anhydrous tetrahydrofuran. The filtrate was combined with o-nitroaniline-p-sulfonyl chloride (11.26 g, 47.63 mmol) and N,N-diisopropylethylamine (9.05 mL, 51.96 mmol) and stirred under an Argon atmosphere for 16 hrs. at ambient temperature. The reaction mixture was diluted with 1N NaHSO4 and dichloromethane and transferred to a separatory funnel. The organic phase was separated and the aqueous layer was extracted twice with dichloromethane. The combined organic layers were washed with 5% aqueous potassium carbonate, dried over anhydrous magnesium sulfate, filtered through a pad of diatomaceous earth and evaporated in vacuo. The residue was purified on flash grade silica gel eluting with 1:1 ethyl acetate : hexane. Fractions containing the product were combined, evaporated in vacuo to a residue and triturated with hexane. The slurry was filtered and the product was dried under high vacuum to provide 4-amino-N-(cyclopentyloxy)-3-nitrobenzenesulfonamide (8.89 g, 68%) as a yellow solid. H1-NMR (chloroform-D3): 1.57 (m, 4H), 1.74 (m, 4H), 4.61 (m, 1H), 6.52 (b, 2H), 6.73 (s, 1H), 6.90 (d, 1H), 7.79 (m, 1H), 8.70 (d, 1H). MS(ESI): 324(M+Na).

Provenance & Evidence