Diisopropylethylamine → methyl (4R)-4-(2-chloro-4-fluoro-phenyl)-6-[(6-oxo-1,3,4,8,9,9a-hexahydropyrazino[1,2-c][1,3]oxazin-2-yl)methyl]-2-thiazol-2-yl-1,4-dihydropyrimidine-5-carboxylate

Participants

Reaction Steps

To a stirred solution of (R)-6-bromomethyl-4-(2-chloro-4-fluoro-phenyl)-2-thiazol-2-yl-1,4-dihydro-pyrimidine-5-carboxylic acid methyl ester (0.072 g, 0.16 mmol) and hexahydro-pyrazino[1,2-c][1,3]oxazin-6-one trifluoro acetitic acid salt (Compound D, crude, 0.25 mmol) in 1,2-dichloroethane (5 mL) was added dropwise DIPEA (0.078 mL, 0.45 mmol). The reaction mixture was stirred at room temperature until the disappearance of starting material. The mixture was diluted with EtOAc (50 mL) and washed successively with saturated aqueous NH4Cl solution and brine. The organic layer was separated and then dried over Na2SO4. The solvent was concentrated in vacuo and the crude product was purified by prep-HPLC to give methyl (4R)-4-(2-chloro-4-fluoro-phenyl)-6-[(6-oxo-1,3,4,8,9,9a-hexahydropyrazino[1,2-c][1,3]oxazin-2-yl)methyl]-2-thiazol-2-yl-1,4-dihydropyrimidine-5-carboxylate (Example 1) as a light yellow solid (11 mg). 1H NMR (400 MHz, METHANOL-d4) d ppm 7.97 (dd, J=3.01, 1.00 Hz, 1H), 7.81 (d, J=3.01 Hz, 1H), 7.46 (dd, J=8.66, 6.15 Hz, 1H), 7.26 (dd, J=8.78, 2.51 Hz, 1H), 7.00-7.13 (m, 1H), 6.19 (d, J=1.76 Hz, 1H), 4.19-4.48 (m, 4H), 4.11 (d, J=16.06 Hz, 1H), 3.76-3.94 (m, 1H), 3.62 (s, 3H), 3.18-3.31 (m, 2H), 2.37-2.80 (m, 3H), 2.11-2.30 (m, 1H), 1.90 (qdd, J=14.37, 14.37, 14.37, 9.22, 5.40 Hz, 1H). MS: calc'd 520 (MH+), measured 520 (MH+).

Provenance & Evidence