Cesium carbonate → ((2R,5R)-5-{6-[(5-Cyano-3-methyl-pyridine-2-carbonyl)-amino]-pyridin-2-yl}-2,5-dimethyl-2-trifluoromethyl-5,6-dihydro-2H-[1,4]oxazin-3-yl)-carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of [(2R,5R)-5-(6-Bromo-pyridin-2-yl)-2,5-dimethyl-2-trifluoromethyl-5,6-dihydro-2H-[1,4]oxazin-3-yl]-carbamic acid tert-butyl ester (60.00 mg, 0.133 mmol), 5-cyano-3-methylpicolinamide (23.52 mg, 0.146 mmol), Xantphos (6.91 mg, 0.012 mmol) and Cs2CO3 (60.50 mg, 0.186 mmol) in dioxane (0.611 ml) was degassed with argon for 5 min, then Pd2 dba3 (3.64 mg, 3.98 μmol) was added and the reaction mixture was stirred at 40° C. for 18 h. The reaction mixture was diluted with H2O and TBME. The phases were separated and the aq. phase was reextracted with TBME. The combined org. phases were washed with brine, dried over Na2SO4, filtered and concentrated. HPLC purification (Alltech Grom Saphir 65 Si 10 μM column, 150×30 mm, gradient n-heptane:EtOAc 0-1.2 min 75:25, 1.2-9 min 0:100, 9-12 min 0:100, flow: 50 ml/min, detection: 254 nm) yielded the title compound as a colourless solid. HPLC RtH4=1.37 min; ESIMS: 533 [(M+H)+]; 1H NMR (400 MHz, CDCl3): δ 11.22 (s, 1H), 10.47 (s, 1H), 8.78 (d, 1H), 8.33 (d, 1H), 7.98 (d, 1H), 7.84-7.80 (m, 1H), 7.13 (d, 1H), 4.37 (d, 1H), 4.11 (d, 1H), 2.88 (s, 3H), 1.64 (s, 3H), 1.57 (br s, 12H).

Provenance & Evidence