2-Thiophenecarbonyl chloride → Tert-butyl 4-(thiophene-2-carbonyl)piperazine-1-carboxylate
Reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[C:6](Cl)=[O:7].[C:9]([O:13][C:14]([N:16]1[CH2:21][CH2:20][NH:19][CH2:18][CH2:17]1)=[O:15])([CH3:12])([CH3:11])[CH3:10]>CN(C1C=CN=CC=1)C.N1C=CC=CC=1>[C:9]([O:13][C:14]([N:16]1[CH2:21][CH2:20][N:19]([C:6]([C:2]2[S:1][CH:5]=[CH:4][CH:3]=2)=[O:7])[CH2:18][CH2:17]1)=[O:15])([CH3:12])([CH3:10])[CH3:11]Participants
5
Procedure
2-Thiophenecarbonylchloride (2.04 g, 1.49 mL) was added to a solution of tert-butyl-1-piperazinecarboxylate (2.5 g, 13.4 mmol) and DMAP (20 mg) in pyridine (15 mL) at 0° C. under N2 atmosphere and stirred at room temperature for overnight. The mixture was poured into ice water, the precipitate was filtered, washed several times with water, and dried to yield white solids (3.5 g, 88%). Mp 76° C. 1H NMR (DMSO-d6): δ 1.42 (s, 12H), 3.40 (m, 4H), 3.61 (m, 4H), 7.12 (m, 1H), 7.43 (d, J=4.1 Hz, 1H), 7.77 (d, J=4.8 Hz, 1H). EIMS m/z 297 (M+1), 319 (M+23). Anal. (C14H20N2O3S)C, H, N.
Workup
- filtrationthe precipitate was filtered
- washwashed several times with water
- customdried
Sources & evidence
- ORD record
- ord-bdecf9fe24d14428aa1e484b92446021
- Source dataset
- uspto-grants-2007_03
- Patent number
- US07192955B2
Reaction notes
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