Diisopropylethylamine → Piperazine, 1-cyclopentyl-4-(4-nitro-2-pyridinyl)-

HRID 1432140Notes

Reaction equation

Cl[C:2]1[CH:7]=[C:6]([N+:8]([O-:10])=[O:9])[CH:5]=[CH:4][N:3]=1.[CH:11]1([N:16]2[CH2:21][CH2:20][NH:19][CH2:18][CH2:17]2)[CH2:15][CH2:14][CH2:13][CH2:12]1.C(N(CC)C(C)C)(C)C>CN(C=O)C.O>[CH:11]1([N:16]2[CH2:17][CH2:18][N:19]([C:2]3[CH:7]=[C:6]([N+:8]([O-:10])=[O:9])[CH:5]=[CH:4][N:3]=3)[CH2:20][CH2:21]2)[CH2:12][CH2:13][CH2:14][CH2:15]1

Participants

Conditions

Temperature: 95 °C

Procedure

A mixture of 5.6 g (35 mmol) 2-chloro-4-nitropyridine, 5.75 g (37 mmol) 1-cyclo-pentyl piperazine and 4.59 g (35 mmol) N,N-diisopropylethylamine in 35 ml DMF and 12 ml water was heated to 95° C. for 3 h. After evaporation to dryness the residue was taken up in 150 ml NaHCO3 aq. and 150 ml ethyl acetate. The aqueous phase was extracted two times with 150 ml ethyl acetate each and the combined organic phases were washed twice with 100 ml NaHCO3 aq each and 100 ml NaCl aq. sat. and dried with MgSO4 and evaporated to dryness. The residue was purified with column chromatography to yield 2.85 g (29%) 1-cyclopentyl-4-(4-nitro-pyridin-2-yl)-piperazine (m/e): 277.3 (MH+; 100%) and 4.47 g (47%) 1-(2-chloro-pyridin-4-yl)-4-cyclopentyl-piperazine (m/e): 266.3 (MH+; 100%).

Workup

customAfter evaporation to dryness the residue
extractionThe aqueous phase was extracted two times with 150 ml ethyl acetate each and the combined organic phases
washwere washed twice with 100 ml NaHCO3 aq each and 100 ml NaCl aq. sat.
dry with materialdried with MgSO4
customevaporated to dryness
customThe residue was purified with column chromatography

Sources & evidence

ORD record: ord-c6dfb305fdab4e00bf3fe5e2074b7a4e
Source dataset: uspto-grants-2009_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07612076B2

Reaction notes

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