Sodium Carbonate → 1-Methyl-4-formylamino-2-pyrrolecarboxylic acid

HRID 270244Notes

Reaction equation

[CH3:1][N:2]1[CH:6]=[C:5]([N+:7]([O-])=O)[CH:4]=[C:3]1[C:10]([OH:12])=[O:11].[H][H].[C:15](=O)([O-])[O-:16].[Na+].[Na+]>[Pd]>[CH3:1][N:2]1[CH:6]=[C:5]([NH:7][CH:15]=[O:16])[CH:4]=[C:3]1[C:10]([OH:12])=[O:11]

Participants

Conditions

Temperature: 2.5 °C

Procedure

1-methyl-4-nitro-2-pyrrolecarboxylic acid (III) (1.0 g, 6.0 mmol) is dissolved in 20 mL of a 1 M sodium carbonate aqueous solution and hydrogenated in presence of 250 mg of 10% Pd/C catalyst. When the uptake of hydrogen has stopped, the catalyst is removed by filtration and the resulting yellow solution, containing the aminoacid (VI), is slowly added to a freshly prepared benzene solution of N-formylimidazole with vigorous stirring. After the addition, the resulting two layers are stirred for additional 15 min and then the organic layer is separated and discarded. The aqueous yellow solution, cooled to 0-5° C., is carefully acidified with formic acid (pH 3.5) with vigorous stirring. The precipitated acid (V) is filtered off and washed with small portions of ice-cold water. There are obtained 0.81 g (yield 80%) of product (V): m.p. 208-210° C.; NMR (DMSO-d6), ppm: 3.85 (s, 3H); 6.75 (d, 1H); 7.35 (d, 1H); 8.15 (s, 1H).

Workup

customthe catalyst is removed by filtration
additionthe resulting yellow solution, containing the aminoacid (VI)
additionis slowly added to a freshly prepared benzene solution of N-formylimidazole with vigorous stirring
additionAfter the addition
customthe organic layer is separated
filtrationThe precipitated acid (V) is filtered off
washwashed with small portions of ice-cold water

Sources & evidence

ORD record: ord-d8064539d53c4035b516b90705aa9b10
Source dataset: uspto-grants-2008_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07449547B2

Reaction notes

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