N#N.[CH3:3][C:4]1([C:9]2[N:10]=[C:11]([CH2:14][OH:15])[S:12][CH:13]=2)[O:8][CH2:7][CH2:6][O:5]1.CCN(CC)CC.[S:23](Cl)([CH3:26])(=[O:25])=[O:24]>C(Cl)Cl.CN(C1C=CN=CC=1)C>[CH3:3][C:4]1([C:9]2[N:10]=[C:11]([CH2:14][O:15][S:23]([CH3:26])(=[O:25])=[O:24])[S:12][CH:13]=2)[O:8][CH2:7][CH2:6][O:5]1
In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of [4-(2-methyl-[1,3]dioxolan-2-yl)-thiazol-2-yl]-methanol (18.460 g, 91.73 mmol) in dry CH2Cl2 (300 mL) was treated at 0° C. with Et3N (16.59 mL, 118.62 mmol) followed by DMAP (1.132 g, 9.17 mmol) and Ms-Cl (9.17 mL, 115.83 mmol). After stirring at 0° C. for 1 h, the reaction was quenched with water (80 mL). The layers were separated and the aq. layer extracted with CH2Cl2 (3×) The org. layer was dried over MgSO4, filtered, and the solvents were removed under reduced pressure to give crude methanesulfonic acid 4-(2-methyl-[1,3]dioxolan-2-yl)-thiazol-2-ylmethyl ester as a brown oil. Part of this crude material (2.756 g, 9.87 mmol) in DMF (20 mL) was added to a solution of 4-nitro-2H-[1,2,3]triazole (10.60 g of a 10% solution in acetone, 9.29 mmol) in DMF (20 mL) pre-treated for 30 min with DIPEA (3.18 mL, 18.59 mmol) and the reaction mixture was stirred overnight at 50° C. Water (25 mL), followed by EA (50 mL) were added. The aq. layer was extracted with EA (50 mL) and the combined org. extracts were dried over Na2SO4, filtered, and the solvents were removed under reduced pressure. Purification of the residue by FC (1:2 hept-EA) gave the title compound as a yellow solid: TLC:rf (1:2 hept-EA)=0.52. LC-MS-conditions 02: tR=0.88 min, [M+H]+=297.84.
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