1-Methylpiperazine → HCID 178480928, compound

Participants

Reaction Steps

A solution of 7-amino-2-methyl-4-(4-oxocyclohexyl)-2,3-dihydro-1H-isoindol-1-one (100.0 mg, 0.3871 mmol) in 1,2-dichloroethane (2.0 mL) was charged with 1-methylpiperazine (58.16 mg, 0.5807 mmol) and sodium triacetoxyborohydride (164.1 mg, 0.7743 mmol). The reaction mixture was stirred at rt for 24 hours. The reaction mixture was quenched with NaHCO3 (10 mL) and extracted with EtOAc (20 mL). The organic layer was washed with brine (10 mL), dried over Na2SO4, filtered and concentrated under reduced pressure to yield a light yellow oil. The crude material was purified and by silica gel chromatography on the combi-flash Rf system using DCM/7M NH3 in MeOH (100:0→90:10) as eluent to afford the cis isomer (76.5 mg, 58%, first eluting product) and the trans isomer (30.0 mg, 23%, second eluting product). Cis isomer: 1H NMR (CDCl3, 400 MHz): δ=1.42-1.56 (m, 4 H), 1.82-1.96 (m, 2 H), 2.06 (d, J=11.87 Hz, 2 H), 2.27 (br. s., 1 H), 2.34 (s, 3 H), 2.38-2.78 (m, 9 H), 3.14 (s, 3 H), 4.31 (s, 2 H), 5.08 (s, 2 H), 6.58 (d, J=8.34 Hz, 1 H), 7.18 (d, J=8.34 Hz, 1 H). MS (ES+): m/z 343.25 [MH+]. Trans isomer: 1H NMR (CDCl3, 400 MHz): δ=1.35-1.75 (m, 7 H), 1.91 (d, J=12.13 Hz, 2 H), 2.03-2.13 (m, 2 H), 2.34 (s, 3 H), 2.47-2.82 (m, 7 H), 3.14 (s, 3 H), 4.28 (s, 2 H), 5.09 (s, 2 H), 6.56 (d, J=8.34 Hz, 1 H), 7.09 (d, J=8.34 Hz, 1 H). MS (ES+): m/z 343.26 [MH+].

Provenance & Evidence