Triethylamine → Tert-butyl 4-(4-cyano-3-nitrophenyl)piperazine-1-carboxylate

HRID 1520111Notes

Reaction equation

Br[C:2]1[CH:9]=[CH:8][C:5]([C:6]#[N:7])=[C:4]([N+:10]([O-:12])=[O:11])[CH:3]=1.Cl.[C:14]([N:21]1[CH2:26][CH2:25][NH:24][CH2:23][CH2:22]1)([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15].CCN(CC)CC>CN(C=O)C>[C:6]([C:5]1[CH:8]=[CH:9][C:2]([N:24]2[CH2:23][CH2:22][N:21]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:26][CH2:25]2)=[CH:3][C:4]=1[N+:10]([O-:12])=[O:11])#[N:7]

Participants

Conditions

Temperature: 70 °C

Procedure

To a solution of a mixture of compound 17 (3 g, 13.27 mmol) and 1-boc-piperazine hydrochloride (3.53 g, 15.92 mmol) in DMF (30 mL) was added Et3N (4.4 mL, 31.8 mmol), and the mixture was heated at 70° C. for 6 h. The mixture was cooled to room temperature, extracted with ethyl acetate (100 mL), and the organic layer was washed with brine (20 mL), dried over Na2SO4 and evaporated. Trituration with diethyl ether afforded 4.27 g (97%) of compound 18 as bright yellow solid, m.p. 138-139° C.; IR (KBr) νmax. cm−1: 3042 (Ar—H), 2252 (CN), 1690 (C═O), 1610, 1520, 1412 (C═C). 1H NMR (500 MHz, DMSO-d6) δ=1.39 (s, 9H, (CH3)3C); 3.44 (br. s, 4H, 2 CH2); 7.19 (dd, 1H, J=2.6, 9.4 Hz, H-5); 7.46 (d, 1H, J=2.7 Hz, H-2); 8.17 (d, 1H, J=2.7 Hz, H-6); 13C NMR (125.7 MHz, DMSO-d6) δ=28.11 (CH3)3C), 45.92 (CH2), 46.02 (CH2), 79.56 (CH3)3C), 109.24 (C-4), 115.61 (C-2), 116.46 (CN), 119.03 (C-6), 128.09 (C-5), 135.85 (C-3), 153.30 (C-1), 154.13 (C═O). Calculated (%) for C16H20N4O4 (332.15); C: 57.82, H: 6.07, N: 16.86. found (%); C: 57.76, H: 6.11, N: 16.80.

Workup

temperatureThe mixture was cooled to room temperature
extractionextracted with ethyl acetate (100 mL)
washthe organic layer was washed with brine (20 mL)
dry with materialdried over Na2SO4
customevaporated

Sources & evidence

ORD record: ord-051b4d12ba794faba152cae954dbc016
Source dataset: uspto-grants-2015_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09073900B2

Reaction notes

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