3-BENZYL-3H-[1,2,3]TRIAZOLO[4,5-D]PYRIMIDIN-7-OL synthesis

Yield:21324-31-2 81%

Reaction Conditions:

with hydrogenchloride;sodium nitrite in tetrahydrofuran;water at 0 - 30;Inert atmosphere;Autoclave;

Steps:

General procedure for diazotization / cyclisation

General procedure: To a stirred solution of amino derivative (1.0 equiv) (obtained from the previous experiments) in THF: water (5: 1, 2 mL 0.502 mmol) was added 2N HCl (3 equiv) followed by NaNO₂(1.5 equiv) in H₂O (0.5 mL 0.502 mmol) at 0^oC. The mixture was stirred for 30 min at 0 C and was allowed to reach room temperature slowly. The stirring was continued for 2-4 h and the progress of the reaction was monitored by TLC. After completion of the reaction the mixture was cooled to 0^oC and the pH was adjusted to 8 using the saturated aqueous NaHCO₃solution. Then the mixture was extracted with EtOAc (3 times). The combined organic layers were collected, washed with water (2 times) and brine, dried over anhydrous Na₂SO₄, filtered and concentrated under a reduced pressure. The resultant crude compound was purified by silica gel column chromatography (100-200 mesh) using 5-10 % MeOH-CH₂Cl₂to afford the desired compounds. (yield: 79- 96 %).

References:

Marepu, Nagaraju;Yeturu, Sunandamma;Pal, Manojit [Bioorganic and Medicinal Chemistry Letters,2018,vol. 28,# 20,p. 3302 - 3306] Location in patent:supporting information