反应详情

To a solution of chlorosulfonyl isocyanate (9.2 μL, 0.11 mmol) in dichloromethane (0.24 mL), at 0° C. and under a nitrogen atmosphere, was added tert-butyl alcohol (10 μL, 0.11 mmol) in a dropwise fashion. The solution was allowed to stir at room temperature for 1 hour to obtain a solution of tert-butyl[chlorosulfonyl]carbamate. In a separate flask, 3-{4-[(2-aminoethyl)amino]-1,2,5-oxadiazol-3-yl}-4-[3-(trifluoromethyl)phenyl]-1,2,4-oxadiazol-5(4H)-one hydroiodide (26 mg, 0.053 mmol) was suspended in dichloromethane (0.5 mL). A nitrogen atmosphere was established and the temperature brought to 0° C. The tert-butyl[chlorosulfonyl]carbamate solution (prepared as above) was added over 5 minutes to the stirred suspension of the amine salt. After 10 minutes, triethylamine (37 μL, 0.27 mmol) was added dropwise. The reaction mixture was stirred at room temperature for 1.5 hours. After concentrating in vacuo, the residue was treated with trifluoroacetic acid (0.5 mL, 6 mmol). This was stirred for 1 hour and the mixture was again concentrated to dryness in vacuo. The dried solids were suspended in methanol (0.5 mL) and a 2.0 N NaOH in water (0.53 mL, 1.1 mmol) was added in one portion. The reaction was heated to 45° C. and stirred for 30 minutes. After neutralization with acetic acid (60 μL, 1.1 mmol), the product was purified by preparative LCMS to give the desired product (8.5 mg, 39%). LCMS calculated for C12H15F3N7O4S (M+H)+: m/z=410.0. 1H NMR (400 MHz, CD3OD): δ 7.36 (t, J=7.8 Hz, 1H), 7.23 (d, J=7.8 Hz, 1H), 7.10 (s, 1H), 7.03 (d, J=7.8 Hz, 1H), 3.48 (m, 2H), 3.29 (m, 2H).

1. custombrought to 0° C
2. concentrationAfter concentrating in vacuo
3. stirringThis was stirred for 1 hour
4. concentrationthe mixture was again concentrated to dryness in vacuo
5. temperatureThe reaction was heated to 45° C.
6. stirringstirred for 30 minutes