Ethyl bromopyruvate → diethyl 5-amino-1H-pyrrole-2,4-dicarboxylate

HRID 567747Notes

Reaction equation

[C:1]([CH2:4][C:5]([O:7][CH2:8][CH3:9])=[O:6])(=[NH:3])[NH2:2].Br[CH2:11][C:12](=O)[C:13]([O:15][CH2:16][CH3:17])=[O:14]>CN1CCCN(C)C1=O>[NH2:3][C:1]1[NH:2][C:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[CH:11][C:4]=1[C:5]([O:7][CH2:8][CH3:9])=[O:6]

Participants

Conditions

Temperature: 60 °C

Procedure

At 0-5° C., 56.0 g (0.43 mol) of ethyl 2-amidinoacetate [for preparation see: Liebigs Ann. Chem., 1561 (1981)] are initially introduced into 172 ml of 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone. 56.0 ml (0.45 mol) of ethyl bromopyruvate are added dropwise in the course of 30 min and the mixture is then warmed to 60° C. for 3 h. The dark-brown reaction solution is poured onto 1 liter of ice water and extracted with 1 liter of ethyl acetate and twice with 0.5 liter of ethyl acetate each time. The organic phases are washed 3 times with 0.5 liter of water and 0.5 liter of brine, dried (Na2SO4) and evaporated. Column chromatography (SiO2, hexane/ethyl acetate [1:1]) and crystallization from diethyl ether-hexane yields 2-amino-3,5-bis(ethoxycarbonyl)-1H-pyrrole; m.p. 147-149° C.; MS: (M)+=226.

Workup

extractionextracted with 1 liter of ethyl acetate and twice with 0.5 liter of ethyl acetate each time
washThe organic phases are washed 3 times with 0.5 liter of water and 0.5 liter of brine
dry with materialdried (Na2SO4)
customevaporated
customColumn chromatography (SiO2, hexane/ethyl acetate [1:1]) and crystallization from diethyl ether-hexane

Sources & evidence

ORD record: ord-7a44bb688d59414186221202ae5a9b99
Source dataset: uspto-grants-2001_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06180636B2

Reaction notes

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