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]1In 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 (745 mg, 3.70 mmol) in dry CH2Cl2 (5 mL) was treated at 0° C. with Et3N (0.67 mL, 4.79 mmol) followed by DMAP (46 mg, 0.37 mmol) and Ms-Cl (0.37 mL, 4.67 mmol). After stirring at 0° C. for 1 h 30, the reaction was quenched with water (5 mL). The org. layer was dried over MgSO4, filtered, and the solvents were removed under reduced pressure to give 1.03 g (quant.) of crude methanesulfonic acid 4-(2-methyl-[1,3]dioxolan-2-yl)-thiazol-2-ylmethyl ester as a yellow oil. Part of this crude material (323 mg) in DMF (2.0 mL) was added to a solution of 4-nitro-2H-[1,2,3]triazole (120 mg, 1.05 mmol) in DMF (2.0 mL) pre-treated for 30 min with DIPEA (0.36 mL, 2.10 mmol) and the reaction mixture was stirred for 24 h at 50° C. Water (10 mL), followed by EA (10 mL) were added. The aq. layer was extracted with EA (10 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 oil: TLC:rf (1:2 hept-EA)=0.33. LC-MS-conditions 02: tR=0.88 min, [M+H]+=298.16.
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