Cesium carbonate → (6-(5-Carbamoyl-1,3,4-thiadiazol-2-yloxy)-1-hydroxy-4-methyl-1,3-dihydrobenzo[c][1,2]oxaborol-3-yl)methanesulfonic acid

Participants

Reaction Steps

To a mixture of methyl (1,6-dihydroxy-4-methyl-1,3-dihydrobenzo[c][1,2]oxaborol-3-yl)methanesulfonate (0.46 g, 1.71 mmol, 1 eq.) and 5-chloro-1,3,4-thiadiazole-2-carboxamide (0.42 g, 2.56 mmol, 1.5 eq.) in 10 ml DMF was added cesium carbonate (2.22 g, 6.82 mmol, 4 eq.) portionwise. The reaction was stirred at room temperature overnight. It was then quenched by water, extracted with EtOAc. The aqueous layer was collected and prep HPLC gave the product as white flakes. 1H NMR (400 MHz, DMSO-d6) δ 8.39 (s, 1H), 8.01 (s, 1H), 7.39 (d, J=2.4 Hz, 1H), 7.27 (d, J=2.4 Hz, 1H), 5.42 (d, 7.6 Hz, 1H), 3.04 (dd, J=14.4, 1.2 Hz, 1H), 2.46 (m, 1H), 2.27 (s, 3H).

Provenance & Evidence