(S)-1-Boc-3-methylpiperazine → tert-butyl (3S)-4-[2-hydroxy-5-(trifluoromethyl)-2,3-dihydro-1H-inden-1-yl]-3-methylpiperazine-1-carboxylate

HRID 2178771Notes

Reaction equation

[F:1][C:2]([F:14])([F:13])[C:3]1[CH:12]=[CH:11][C:10]2[CH:8]3[O:9][CH:7]3[CH2:6][C:5]=2[CH:4]=1.[CH3:15][C@@H:16]1[NH:21][CH2:20][CH2:19][N:18]([C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])[CH2:17]1>C(O)C>[OH:9][CH:7]1[CH2:6][C:5]2[C:10](=[CH:11][CH:12]=[C:3]([C:2]([F:14])([F:13])[F:1])[CH:4]=2)[CH:8]1[N:21]1[CH2:20][CH2:19][N:18]([C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])[CH2:17][C@@H:16]1[CH3:15]

Participants

Conditions

Temperature: 95 °C

Procedure

A mixture of 4-(trifluoromethyl)-6,6a-dihydro-1aH-indeno[1,2-b]oxirene (1.2 g, 6.0 mmol) and tert-butyl (3S)-3-methylpiperazine-1-carboxylate (1.4 g, 7.2 mol) in ethanol (20 mL) was refluxed overnight. Another gram of tert-butyl (3S)-3-methylpiperazine-1-carboxylate was added. The mixture was transferred into a sealed flask and heated to 95° C. for 2 days. The solvent was concentrated and the residue was purified by flash chromatography eluting with 25% EtOAc/hexane, followed by 5% MeOH/EtOAc+0.5% concentrated NH4OH. Two isomers were isolated. Isomer 1 (fast moving isomer): 0.45 g; MS calculated for the C20H27F3N2O3 (M+H)+401; found 401.1. Isomer 2 (slow moving isomer): 0.38 g; MS found 401.1.

Workup

temperaturewas refluxed overnight
customThe mixture was transferred into a sealed flask
concentrationThe solvent was concentrated
customthe residue was purified by flash chromatography
washeluting with 25% EtOAc/hexane
customTwo isomers were isolated

Sources & evidence

ORD record: ord-e118488ae99a4d65a9e34ef20aaa27fa
Source dataset: uspto-grants-2015_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09067921B2

Reaction notes

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