[NH2:1][C:2]1[S:3][CH:4]=[N:5][N:6]=1.C([Li])CCC.Cl[Si](C)(C)C.[CH3:17][CH2:18][C:19](=[O:22])[CH2:20][CH3:21]>C1COCC1>[NH2:1][C:2]1[S:3][C:4]([C:19]([OH:22])([CH2:20][CH3:21])[CH2:18][CH3:17])=[N:5][N:6]=1To a −78° C. solution of 2-amino-1,3,4-thiadiazole (commercially available) (2.5 g, 24.72 mmol) in THF (200 mL, 0.1M) was added first n-butyllithium 1.6M hexanes (30.9 mL, 49.4 mmol) followed 15 min later by chlorotrimethylsilane (6.27 mL, 49.4 mmol). The temperature raised to −20° C. for 15 min and cooled back to −78° C. More n-butyllithium 1.6M hexanes (15.45 mL, 24.72 mmol) was added followed 15 min later by 3-pentanone (2.62 mL, 24.72 mmol). The solution was then warmed to rt (overnight). The reaction mixture was quenched with a saturated NH4Cl solution and THF was removed under vacuum. The aqueous phase was extracted with EtOAc (3×) and the combined organic layers were washed with brine, dried over MgSO4 and concentrated. The crude residue obtained was purified by column chromatography (100% EtOAc) to yield the title compound. 1H NMR (400 MHz, acetone-d6): δ 6.3 (bs, 2H), 4.4 (bs, 1H), 2.0-1.7 (m, 4H), 0.9 (t, 6H).
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