Sodium Carbonate → 3-Methoxy-4-(5-(methyl(2,2,6,6-tetramethylpiperidin-4-yl)amino)-1,3,4-thiadiazol-2-yl)phenol

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of tert-butyl(3-methoxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenoxy)dimethylsilane (Intermediate 3) (3.28 g, 9.00 mmol) and 5-bromo-N-methyl-N-(2,2,6,6-tetramethylpiperidin-4-yl)-1,3,4-thiadiazol-2-amine (Intermediate 4) (1 g, 6.00 mmol) in dioxane (48 mL) under nitrogen was added Pd(PPh3)4 (0.347 g, 0.30 mmol) followed by a solution of Na2CO3 (1.272 g, 12.00 mmol) in water (12 mL). The resulting mixture was refluxed at 120° C. for 18 hours. The reaction mixture was cooled to room temperature, then diluted with EtOAc (150 mL) and washed with water (100 mL). The organic phase was separated and the aqueous phase re-extracted with EtOAc (150 mL). The combined organics were dried over MgSO4, filtered, and the filtrate concentrated in vacuo to afford an oily brown residue. The residue was suspended in EtOAc (10 mL) and sonicated, then the resulting suspension was filtered under vacuum to afford the crude product as an off-white solid. The crude mixture was purified by flash chromatography using 3% [7M NH3 in MeOH]/DCM as the eluent to afford the title compound as a pale yellow glass-like solid (0.534 g, 23% yield). LC-MS: Rt 0.75 min; MS m/z 377.3 [M+H]+ [Method A]. 1H NMR (400 MHz, DMSO-d6) δ ppm 9.99 (br. s., 1H), 7.88 (d, J=8.59 Hz, 1H), 6.54 (d, J=2.53 Hz, 1H), 6.50 (dd, J=8.34, 2.27 Hz, 1H), 4.34-4.25 (m, 1H), 3.86 (s, 3H), 2.94 (s, 3H), 1.59 (dd, J=11.62, 3.03 Hz, 2H), 1.40 (t, J=12.38 Hz, 2H), 1.26 (br. s., 1H), 1.20 (s, 6H), 1.08 (s, 6H).

Provenance & Evidence