2,4-Difluorobenzoic acid → t-Butyl 4-(2,4-difluorobenzoyl)piperazine-1-carboxylate

HRID 639465

Reaction equation

HRID 639465 reaction equation
[F:1][C:2]1[CH:10]=[C:9]([F:11])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=O.CCN(C(C)C)C(C)C.C1C=CC2N(O)N=NC=2C=1.[N:31]1([C:37]([O:39][C:40]([CH3:43])([CH3:42])[CH3:41])=[O:38])[CH2:36][CH2:35][NH:34][CH2:33][CH2:32]1.CCN=C=NCCCN(C)C.Cl>C(Cl)Cl.O>[F:1][C:2]1[CH:10]=[C:9]([F:11])[CH:8]=[CH:7][C:3]=1[C:4]([N:34]1[CH2:33][CH2:32][N:31]([C:37]([O:39][C:40]([CH3:43])([CH3:42])[CH3:41])=[O:38])[CH2:36][CH2:35]1)=[O:6]

Participants

8

Reactant 5

HCID 741022,4-Difluorobenzoic acidHCID 757711-HydroxybenzotriazoleHCID 81531DiisopropylethylamineHCID 143452tert-Butyl piperazine-1-carboxylateHCID 27239391,3-Propanediamine, N'-(ethylcarbonimidoyl)-N,N-dimethyl-, monohydrochloride

Product 1

HCID 68414338t-Butyl 4-(2,4-difluorobenzoyl)piperazine-1-carboxylate

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent

Procedure

To a solution of 3.0 g (19 mmol) of 2,4-difluorobenzoic acid and 4 mL of DIEA (1.2 equiv.) in 40 mL of dry DCM is added 3.08 g (1.2 equiv) of HOBt and 4.2 g (22.55 mmol) of t-butyl piperazine-1-carboxylate, and the mixture was stirred at RT for 30 min. 4.4 g (11 equiv.) of EDCl are added and the reaction mixture is stirred overnight at RT. Water is added and the resulting mixture is extracted with DCM. The organic layer is dried over anhydrous MgSO4, filtered and concentrated in vacuo to obtain t-butyl 4-(2,4-difluorobenzoyi)piperazine-1-carboxylate as a yellow oil: 1H NMR (CDCl3, 400 MHz) δ 1.47 (s, 9H), 3.30 (m, 2H), 3.41 (m, 2H), 3.53 (m, 2H), 3.76 (m, 2H), 6.86 (dt, 1H, J=8.8 Hz and 0.8 Hz), 6.97 (dt, 1H, J=8.8 Hz and 0.8 Hz), 7.41 (dd, 1H, J=14.4 Hz and 7.2 Hz).

Workup

  1. stirringthe reaction mixture is stirred overnight at RT
  2. extractionthe resulting mixture is extracted with DCM
  3. dry with materialThe organic layer is dried over anhydrous MgSO4
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-82a25cea578d45319caaf2457edebde3
Source dataset
uspto-grants-2010_04
Patent number
US07691869B2

Linked notes

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