Trifluoroacetic acid → 4-(2,3-dihydro-1H-pyrido[2,3-b][1,4]thiazin-7-yl)morpholine

Participants

Reaction Steps

To a stirred solution of tert-butyl 7-morpholino-2,3-dihydro-1H-pyrido[2,3-b]-[1,4]thiazine-1-carboxylate (280 mg, 0.83 mmol) in DCM (2.0 mL) was added TFA (3.2 mL, 41.5 mmol). The reaction was stirred at rt for 2 h and evaporated in vacuo. The resulting residue was dissolved in DCM (40 mL) and washed with NaHCO3 (20 mL, saturated aqueous solution). The separated organic layer was dried over MgSO4, filtered and evaporated in vacuo to give 4-(2,3-dihydro-1H-pyrido[2,3-b][1,4]thiazin-7-yl)morpholine as a white solid. 1H NMR (400 MHz, chloroform-d) δ ppm 7.62 (1H, d, J=2.5 Hz), 6.26 (1H, d, J=2.5 Hz), 3.82-3.87 (4H, m), 3.59-3.63 (2H, m), 3.13-3.17 (2H, m), 3.06-3.10 (4H, m). Mass Spectrum (ESI) m/e=238.2 (M+1).

Provenance & Evidence