Phosphorus pentachloride → 4-(2-tert-butyl-4-nitro-1H-pyrrole-5-carbonyl)-3,3-dimethylpiperazin-2-one

HRID 18933Notes

Reaction equation

HRID 18933 reaction equation
[C:1]([C:5]1[NH:9][C:8]([C:10]([OH:12])=O)=[C:7]([N+:13]([O-:15])=[O:14])[CH:6]=1)([CH3:4])([CH3:3])[CH3:2].P(Cl)(Cl)(Cl)(Cl)Cl.[CH3:22][C:23]1([CH3:30])[NH:28][CH2:27][CH2:26][NH:25][C:24]1=[O:29].CCN(C(C)C)C(C)C>ClCCl>[C:1]([C:5]1[NH:9][C:8]([C:10]([N:28]2[CH2:27][CH2:26][NH:25][C:24](=[O:29])[C:23]2([CH3:30])[CH3:22])=[O:12])=[C:7]([N+:13]([O-:15])=[O:14])[CH:6]=1)([CH3:2])([CH3:3])[CH3:4]

Participants

6

Reactant 4

HCID 24819Phosphorus pentachlorideHCID 81531DiisopropylethylamineHCID 2111572-Piperazinone, 3,3-dimethyl-HCID 183223915-tert-butyl-3-nitro-1H-pyrrole-2-carboxylic acid

Product 1

HCID 586792724-(2-tert-butyl-4-nitro-1H-pyrrole-5-carbonyl)-3,3-dimethylpiperazin-2-oneYield 53.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent3×

Procedure

The previously prepared 5-tert-butyl-3-nitro-1H-pyrrole-2-carboxylic acid (0.203 g, 1.11 mmol) and PCl5 (0.232 g, 1.11 mmol) were dissolved in dichloromethane (4 mL) and stirred at room temperature for 5 minutes. The resulting solution was added in one portion to a solution of 3,3-dimethylpiperazin-2-one (0.214 g, 1.67 mmol) and DIEA (0.288 g, 2.23 mmol) in dichloromethane (3 mL) and stirred at room temperature for 5 minutes. The reaction mixture was diluted with dichloromethane and washed sequentially with 1N aqueous HCl, saturated sodium bicarbonate, dried and the solvent removed under vacuum. The crude product was purified by chromatographic column (silica gel, dichloromethane:methanol, 95:5) to afford 0.190 g of expected 4-(2-tert-butyl-4-nitro-1H-pyrrole-5-carbonyl)-3,3-dimethylpiperazin-2-one.

Workup

  1. stirringstirred at room temperature for 5 minutes
  2. washwashed sequentially with 1N aqueous HCl, saturated sodium bicarbonate
  3. customdried
  4. customthe solvent removed under vacuum
  5. customThe crude product was purified by chromatographic column (silica gel, dichloromethane:methanol, 95:5)

Sources & evidence

ORD record
ord-322741f3750e433294754e2aba2b83fd
Source dataset
uspto-grants-2010_06
Patent number
US07741479B2

Reaction notes

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