Hydrochloric Acid → (E)-4-butyramido-1-methyl-2-pyrroleacrylic acid

HRID 1069108Notes

Reaction equation

[C:1]([NH:6][C:7]1[CH:8]=[C:9](/[CH:13]=[CH:14]/[C:15]([O:17]C)=[O:16])[N:10]([CH3:12])[CH:11]=1)(=[O:5])[CH2:2][CH2:3][CH3:4].[OH-].[Na+].Cl>CO>[C:1]([NH:6][C:7]1[CH:8]=[C:9](/[CH:13]=[CH:14]/[C:15]([OH:17])=[O:16])[N:10]([CH3:12])[CH:11]=1)(=[O:5])[CH2:2][CH2:3][CH3:4]

Participants

Conditions

Temperature: 0 °C

Procedure

A solution of 4 (0.167 g, 0.667 mmol) and 0.2 M aqueous NaOH (5.7 mL, 1.13 mmol) in MeOH (10 mL) was heated under reflux for 50 min. The mixture was cooled to 0° C., 2 M aqueous HCl (0.67 mL, 1.33 mmol) was added, and the mixture was poured onto ice (50 g). The precipitate that formed was collected by filtration and washed with water to give (E)-4-butyramido-1-methyl-2-pyrroleacrylic acid (5) as yellow needles (0.133 g, 85%) mp 74-76° C. (dec.) and 165-166° C. (with evolution of gas). 1H NMR [(CD3)2SO] δ12.02 (br s, 1 H, CO2H), 9.76 (br s, 1 H, CONH), 7.44 (d, J=15.6 Hz, 1 H, H-β), 7.27 (d, J=1.6 Hz, 1 H, H-5), 6.53 (d, J=1.6 Hz, 1 H, H-3), 6.02 (d, J=15.6 Hz, 1 H, H-α), 3.66 (s, 3 H, NCH3), 2.19 (t, J=7.3 Hz, 2 H, CH2CH2CH3), 1.57 (sx, J=7.3 Hz, 2 H, CH2CH2CH3), 0.88 (t, J=7.3 Hz, 3 H, CH2CH2CH3). 13C NMR δ169.2, 168.0 (NHCO, CO2), 131.9, 117.8, 113.6, 101.9 (C-3, 5, α, β), 125.8, 124.2 (C-2, 4), 37.5 (CH2CH2CH3), 33.6 (NCH3), 18.7 (CH2CH2CH3), 13.6 (CH2CH2CH3) Anal. Calculated for C12H16N2O4: C, 61.0; H, 6.8; N, 11.9. Found: C, C, 60.8; H, 8.4; N, 11.7%.

Workup

temperatureunder reflux for 50 min
additionthe mixture was poured onto ice (50 g)
customThe precipitate that formed
filtrationwas collected by filtration
washwashed with water

Sources & evidence

ORD record: ord-ceeaf4b89d8d4b4fadedae54c5f99121
Source dataset: uspto-grants-2001_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06251933B1

Reaction notes

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