Reaction Steps
(S)-4-(4-((6-oxo-6,6a,7,8,9,10-hexahydro-5H-dipyrido[1,2-a:3′,2′-e]pyrazin-3-yl)methyl)piperazin-1-yl)benzoic acid (122 mg, 0.29 mmol) was taken up in DMF (2.9 mL). To the mixture was added N-ethyl-N-isopropylpropan-2-amine (152 μl, 0.87 mmol), O-(7-azabenzotriazole-1-yl)-N,N,N′N′-tetramethyluronium hexafluorophosphate (165 mg, 0.434 mmol), and ethanamine hydrochloride (26.0 mg, 0.318 mmol). The reaction was stirred at room temperature overnight. The reaction was purified via HPLC (10-80 MeCN/H2O, TFA buffered). The fractions were collected and lyophilized to yield 135 mg (85%) of the product as a white solid. 1H NMR (DMSO-d6) δ (ppm): 10.82 (s, 1H), 9.83 (br. s., 1H), 8.25 (t, J=5.6 Hz, 1H), 7.84 (d, J=2.0 Hz, 1H), 7.77 (d, J=8.8 Hz, 2H), 6.94-7.12 (m, 3H), 4.59 (d, J=13.1 Hz, 1H), 4.27 (br. s., 2H), 3.85-4.10 (m, 3H), 3.43 (d, J=10.4 Hz, 2H), 3.21-3.30 (m, 2H), 2.95-3.19 (m, 4H), 2.61-2.72 (m, 1H), 2.05 (d, J=11.8 Hz, 1H), 1.87 (d, J=12.4 Hz, 1H), 1.66 (d, J=12.1 Hz, 1H), 1.31-1.62 (m, 3H), 1.09 (t, J=7.2 Hz, 3H). [M+H] calc'd for C23H27N5O3, 449. found, 449. MP: 232.6° C.
