The title compound was made in two steps using a similar process to that described in example Z-2, 16 (25 mg, 0.055 mmol) and free based [(3S)-3-aminobutyl]tetrahydro-2H-thiopyran-4-ylamine (48 mg, 0.26 mmol) were reacted in dichloromethane (2 mL) with acetic acid to give (4S,12aS)—N-[(4-fluorophenyl)methyl]-4-methyl-6,8-dioxo-7-[(phenylmethyl)oxy]-1-(tetrahydro-2H-thiopyran-4-yl)-1,2,3,4,6,8,12,12a-octahydropyrido[1′,2′;4,5]pyrazino[1,2-a]pyrimidine-9-carboxamide (16 mg, 49%) as a film. This material was debenzylated in a second step in a manner similar to Z-26 to give (4S,12aS)—N-[(4-fluorophenyl)methyl]-7-hydroxy-4-methyl-6,8-dioxo-1-(tetrahydro-2H-thiopyran-4-yl)-1,2,3,4,6,8,12,12a-octahydropyrido[1′,2′:4,5]pyrazino[1,2-a]pyrimidine-9-carboxamide (8 mg, 59%) as an off-white solid, 1H NMR (400 MHz, CDCl3) δ 1.30 (d, J=7.2 Hz, 3H), 1.53-1.58 (m, 1H), 1.72-2.10 (m, 5H), 2.56-2.76 (m, 5H), 2.84-2.87 (m, 2H), 4.18 (dd, J=2.8, 14.0 Hz, 1H), 4.26 (dd, J=3.4, 14.2 Hz, 1H), 4.92-4.97 (m, 1H), 6.96-7.00 (m, 2H), 7.29-7.36 (m, 2H), 8.31 (s, 1H), 10.48 (m, 1H), 12.48 (br, 1H); ES+ MS; 501 (M+1).
