Trifluoroacetic acid → (S)-1-methyl-10-((S)-3-methyl-pyrrolidin-3-yl)-3,5-dihydro-10H-6-oxa-3,4,10,11b-tetraaza-cyclopenta[b]phenanthren-2-one

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Reaction Steps

To a solution of (S)-3-[(S)-7-((E)-2-ethoxy-vinyl)-4-methyl-3-oxo-2,3,4,10-tetrahydro-9-oxa-1,2,4a-triaza-phenanthren-6-ylamino]-3-methyl-pyrrolidine-1-carboxylic acid tert-butyl ester (0.115 g, 0.273 mmol) in DCM (2 mL) was added TFA (1 mL) and the reaction mixture was stirred at ambient temperature for 1 h. The solvent was removed in vacuo and the residue was purified by prep-TLC (eluting with 15% MeOH in DCM) to give (S)-1-methyl-10-((S)-3-methyl-pyrrolidin-3-yl)-3,5-dihydro-10H-6-oxa-3,4,10,11b-tetraaza-cyclopenta[b]phenanthren-2-one (0.020 g, 25%, SFC (Table 1, Method 53) Rt=1.81 min) as a white solid. 1H-NMR (400 MHz, methanol-d4) δ 7.41 (d, J=3.2 Hz, 1H), 7.25 (s, 1H), 7.22 (s, 1H), 6.49 (d, J=3.2 Hz, 1H), 5.11 (q J=6.8 Hz, 1H), 4.62-4.54 (d, J=13.6 Hz, 2H), 4.16-4.09 (m, 1H), 3.88-3.82 (m, 1H), 3.67-3.47 (m, 2H), 3.10-2.97 (m, 1H), 2.71-2.59 (m, 1H), 1.78 (s, 3H), 1.49 (d, J=6.8 Hz, 3H). LC/MS (Table 1, Method 5) Rt=1.916 min; MS m/z: 340 [M+1]+.

Provenance & Evidence