Hydrochloric Acid → 3-{2-[6-(3-ethoxyphenyl)-2-oxo-1,2-dihydroindol-3-ylidenemethyl]-4-methyl-1H-pyrrol-3-yl}-propionic acid

HRID 1860955Notes

Reaction equation

[C:1]([CH2:4][CH2:5][C:6]1[C:7]([CH3:34])=[C:8](C(O)=O)[NH:9][C:10]=1[CH:11]=[C:12]1[C:20]2[C:15](=[CH:16][C:17]([C:21]3[CH:26]=[CH:25][CH:24]=[C:23]([O:27][CH2:28][CH3:29])[CH:22]=3)=[CH:18][CH:19]=2)[NH:14][C:13]1=[O:30])([OH:3])=[O:2].[OH-].[K+].O.Cl>C(O)CO>[CH2:28]([O:27][C:23]1[CH:22]=[C:21]([C:17]2[CH:16]=[C:15]3[C:20]([C:12](=[CH:11][C:10]4[NH:9][CH:8]=[C:7]([CH3:34])[C:6]=4[CH2:5][CH2:4][C:1]([OH:3])=[O:2])[C:13](=[O:30])[NH:14]3)=[CH:19][CH:18]=2)[CH:26]=[CH:25][CH:24]=1)[CH3:29]

Participants

Conditions

Temperature: 100 °C

Procedure

4-(2-Carboxyethyl)-5-[6-(3-ethoxyphenyl)-2-oxo-1,2-dihydroindol-3-ylidenemethyl]-3-methyl-1H-pyrrole-2-carboxylic acid (350 mg) suspended in ethylene glycol (5 mL) was held in a sealed tube in a pre-heated oil bath at 200° C. for 2.5 hours. The reaction mixture was cooled to 100° C. and potassium hydroxide (4 pellets) was added. It was then stirred at 100° C. for 2 hours. The reaction mixture was cooled, poured into water, and acidified with 2 N hydrochloric acid to pH 2. The precipitate was filtered, washed with water, and dried in a vacuum oven overnight. The crude solid was purified on a silica gel column using 33:66:1 ethyl acetate:hexanes:glacial acetic acid to give 140 mg (44%) of 3-{2-[6-(3-ethoxyphenyl)-2-oxo-1,2-dihydroindol-3-ylidenemethyl]-4-methyl-1H-pyrrol-3-yl}-propionic acid as a brown solid.

Workup

temperatureThe reaction mixture was cooled
filtrationThe precipitate was filtered
washwashed with water
customdried in a vacuum oven overnight
customThe crude solid was purified on a silica gel column

Sources & evidence

ORD record: ord-df6ad86e8181417b85057d573f817c1f
Source dataset: uspto-grants-2003_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06531502B1

Reaction notes

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