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

HRID 369864Notes

Reaction equation

[CH2:1]([O:3][C:4](=[O:9])[CH2:5][C:6](=[NH:8])[NH2:7])[CH3:2].[CH2:10]([O:12][C:13](=[O:18])[C:14]([CH2:16]Br)=O)[CH3:11]>CN1C(=O)N(C)CCC1>[NH2:8][C:6]1[NH:7][C:14]([C:13]([O:12][CH2:10][CH3:11])=[O:18])=[CH:16][C:5]=1[C:4]([O:3][CH2:1][CH3:2])=[O:9]

Participants

Conditions

Temperature: 60 °C

Procedure

At 0-5° C., 56.0 g (0.43 mol) of 2-amidino-acetic acid ethyl ester [for preparation see: Liebigs Ann. Chem., 1561 (1981)] are introduced into 172 ml of DMPU. 56.0 ml (0.45 mol) of bromopyruvic acid ethyl ester are added dropwise thereto within the course of 30 min and the reaction mixture is then heated at 60° C. for 3 hours. The dark-brown reaction solution is poured into 1 liter of ice-water and extracted with 1 liter of ethyl acetate and twice with a 0.5 liter of ethyl acetate each time. The organic phases are washed three times with a 0.5 liter of water and a 0.5 liter of brine, dried (Na2SO4) and concentrated by evaporation. Column chromatography (SiO2, hexane/ethyl acetate [1:1]) and crystallization from diethyl ether/hexane yield the title compound; m.p. 147-149° C.; MS: (M)+ =226.

Workup

extractionextracted with 1 liter of ethyl acetate and twice with a 0.5 liter of ethyl acetate each time
washThe organic phases are washed three times with a 0.5 liter of water
dry with materiala 0.5 liter of brine, dried (Na2SO4)
concentrationconcentrated by evaporation
customColumn chromatography (SiO2, hexane/ethyl acetate [1:1]) and crystallization from diethyl ether/hexane

Sources & evidence

ORD record: ord-2d7418f9d36e4742b1f9aafc72cf9455
Source dataset: uspto-grants-2000_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06140332

Reaction notes

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