Potassium Carbonate → 2-(3,5-Dichlorophenyl)-1,3-dioxo-hexahydro-imidazo[1,5-a]pyrazine-7-carboxylic Acid Tert-Butyl Ester

HRID 49976

Reaction equation

HRID 49976 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([N:9]=[C:10]=[O:11])[CH:5]=[C:6]([Cl:8])[CH:7]=1.C([O:14][C:15]([CH:17]1[NH:22][CH2:21][CH2:20][N:19]([C:23]([O:25][C:26]([CH3:29])([CH3:28])[CH3:27])=[O:24])[CH2:18]1)=O)C.C(=O)([O-])[O-].[K+].[K+]>C(Cl)Cl>[C:26]([O:25][C:23]([N:19]1[CH2:20][CH2:21][N:22]2[C:10](=[O:11])[N:9]([C:4]3[CH:3]=[C:2]([Cl:1])[CH:7]=[C:6]([Cl:8])[CH:5]=3)[C:15](=[O:14])[CH:17]2[CH2:18]1)=[O:24])([CH3:29])([CH3:28])[CH3:27]

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 944603,5-Dichlorophenyl isocyanateHCID 114026711-tert-Butyl 3-ethyl piperazine-1,3-dicarboxylate

Product 1

HCID 224792022-(3,5-Dichlorophenyl)-1,3-dioxo-hexahydro-imidazo[1,5-a]pyrazine-7-carboxylic Acid Tert-Butyl EsterYield 136.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
20 °C

Procedure

3,5-Dichlorophenyl isocyanate (2.85 g, 15.2 mmol) was added portionwise to a mixture of piperazine-1,3-dicarboxylic acid 1-tert-butyl ester 3-ethyl ester (2.61 g, 10.1 mmol, prepared as described in Bioorg. Med. Chem. Lett. 1999, 9, 1121-6) and potassium carbonate (1.68 g, 12.1 mmol) in DCM (30 mL) at 5° C. After 30 min at 5° C., the reaction mixture was stirred at 20° C. for 48 h. The white precipitate was discarded and the filtrate concentrated in vacuo to give an oil (5.5 g) which was chromatographed over silica gel (CH2Cl2), to yield the above compound (2.77 g) as a white solid. Mp=144° C.

Workup

  1. concentrationthe filtrate concentrated in vacuo

Sources & evidence

ORD record
ord-e46489ca004e4266b9dcc6048fdf3da3
Source dataset
uspto-grants-2004_03
Patent number
US06710064B2

Linked notes

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