2-Chlorobenzylamine → 3-(2-methylsulfanyl-pyrimidin-4-yl)-1-oxo-6,7-dihydro-1H,5H-pyrazolo[1,2-a]pyrazole-2-carboxylic acid 2-chloro-benzylamide

Participants

Reaction Steps

To a solution of 3-(2-methylsulfanyl-pyrimidin-4-yl)-1-oxo-6,7-dihydro-1H,5H-pyrazolo[1,2-a]pyrazole-2-carboxylic acid, 14, (0.23 g, 0.78 mmol) and 2-chlorobenzylamine (0.10 mL, 0.78 mmol) in DMF (3 mL) is added 1-hydroxybenzotriazole (0.21 g, 1.57 mmol) and then 1-(3-dimethylamino-propyl)-3-ethylcarbodiimide hydrochloride (0.18 g, 0.94 mmol). The reaction solution is stirred at room temperature for 6 days then poured into aqueous saturated NaHCO3. The aqueous phase is extracted with three times with EtOAc and the combined organic phases are washed with aqueous saturated NH4Cl, and H2O, dried (MgSO4), filtered and concentrated in vacuo to afford the desired product which is used without further purification: 1H NMR (300 MHz, CDCl3) δ 9.49 (bd s, NH), 8.69 (d, J=5.1 Hz, 1H), 8.16 (d, J=5.1 Hz, 1H), 7.44-7.37 (m, 2H), 7.25-7.19 (m, 2H), 4.70 (d, J=5.4 Hz, 2H), 4.41 (t, J=7.2 Hz, 2H), 4.14 (t, J=7.2 Hz, 2H), 2.78 (dd, J=7.5, 7.5, 7.5, 7.5 Hz, 2H), 2.06 (s, 3H); ESI+ MS: m/z (rel intensity) 415.9 (100, M++H).

Provenance & Evidence