Potassium Carbonate → 4-(6-Morpholin-4-yl-4-oxo-4H-pyran-2-yl)-phenothiazine-10-carboxylic Acid tert-Butyl Ester

Participants

Reaction Conditions

Reaction Steps

Powdered potassium carbonate (2.03 g, 14.68 mmol) and 2-chloro-6-morpholin-4-yl-pyran-4-one (3) (1.44 g, 6.70 mmol) were added to a stirred solution of 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenothiazine-10-carboxylic acid tert-butyl ester (2.85 g, 6.70 mmol) in anhydrous dioxane (20 ml) and the mixture degassed (sonication for 20 minutes then saturated with N2) thoroughly. Tetrakis (triphenylphosphine) palladium was then added in a single portion and the mixture degassed (sonication for 20 minutes then saturated with N2) once again before a reflux condenser was attached and the mixture heated to 100° C. under a nitrogen atmosphere for 20 hours. Water (30 ml) was added and the mixture extracted with EtOAc (3×30 ml). The organic extracts were then dried using MgSO4, filtered and concentrated in vacuo to yield a dark brown, crystalline solid (3.21 g, 100%) that was taken forward with no further purification. m/z (LC-MS, ESP): 479 [M+H]+, RT=4.55 mins.

Provenance & Evidence