3-Amino-2-pyrazinecarboxylic acid → 3-(1-ethyl-1H-imidazo[4,5-c]pyridin-2-yl)pyrazin-2-amine

HRID 1394229Notes

Reaction equation

[CH2:1]([NH:3][C:4]1[CH:9]=[CH:8][N:7]=[CH:6][C:5]=1[NH2:10])[CH3:2].[NH2:11][C:12]1[C:13]([C:18](O)=O)=[N:14][CH:15]=[CH:16][N:17]=1>C(OCC)C>[CH2:1]([N:3]1[C:4]2[CH:9]=[CH:8][N:7]=[CH:6][C:5]=2[N:10]=[C:18]1[C:13]1[C:12]([NH2:11])=[N:17][CH:16]=[CH:15][N:14]=1)[CH3:2]

Participants

Conditions

Temperature: 195 °C

Procedure

To polyphosphoric acid, preheated to 130° C., was added in one portion an intimate mixture of the product of Example 1 Step 2 (206 mg, 1.5 mmol) and 3-aminopyrazine-2-carboxylic acid (230 mg, 1.65 mmol). The temperature was increased to 195° C. for 1 hour and then cooled back to 130° C. for a further 1 hour. The viscous oil was poured on to ice containing saturated sodium carbonate solution and diethyl ether (5 ml) and the aqueous solution was extracted with chloroform (×5). The combined organic extracts were washed with brine, dried over anhydrous magnesium sulfate and concentrated in vacuo. The crude solid was purified by silica gel chromatography eluting with a gradient of dichloromethane to 0.880 ammonia:ethanol:dichloromethane (1:9:40), to afford the title compound, (20 mg, 6%); MS (ES+) m/e 241 [M+H]+.

Workup

custompreheated to 130° C.
additionwas added in one portion
temperaturecooled back to 130° C. for a further 1 hour
extractionthe aqueous solution was extracted with chloroform (×5)
washThe combined organic extracts were washed with brine
dry with materialdried over anhydrous magnesium sulfate
concentrationconcentrated in vacuo
customThe crude solid was purified by silica gel chromatography
washeluting with a gradient of dichloromethane to 0.880 ammonia:ethanol:dichloromethane (1:9:40)

Sources & evidence

ORD record: ord-e183ad9509a64a838c00d1b788cead8e
Source dataset: uspto-grants-2008_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07348339B2

Reaction notes

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