Hydrochloric Acid → HCID 20550582, compound

HRID 2164127Notes

Reaction equation

HRID 2164127 reaction equation
[OH-].[Na+].[C:3]([NH:6][C:7]1[C:8](=[O:21])[O:9][CH:10]=[C:11]([C:13]2[CH:18]=[CH:17][C:16]([CH3:19])=[CH:15][C:14]=2[NH2:20])[CH:12]=1)(=[O:5])[CH3:4].O1CCCC1.Cl>O>[C:3]([NH:6]/[C:7](=[CH:12]/[C:11]1[C:13]2[C:14](=[CH:15][C:16]([CH3:19])=[CH:17][CH:18]=2)[NH:20][CH:10]=1)/[C:8]([OH:9])=[O:21])(=[O:5])[CH3:4]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 8028TetrahydrofuranHCID 14798Sodium HydroxideHCID 20344320HCID 20344320, compound

Product 1

HCID 20550582HCID 20550582, compoundYield 61%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
5 °C

Procedure

110 ml. of 1 N sodium hydroxide were added dropwise over 30 minutes to a mixture of 26.95 g. (10.2 mmol) of crude 3-acetamido-5-(2-amino-4-methylphenyl)-2H-pyran-2-one in 200 ml. of tetrahydrofuran and 200 ml. of water under a nitrogen atmosphere. The resulting dark suspension was stirred for 30 minutes. 110 ml. of 1 N hydrochloric acid were added dropwise to the dark suspension. After removal of the tetrahydrofuran in vacuo and adjustment to pH 3, the dark suspension was cooled to 5° C., and filtered. The filter cake (21.1 g.) was dissolved in 1100 ml. of boiling methanol, treated with 2.0 g. of charcoal for 10 minutes and filtered through a bed of diatomaceous earth (which was washed with 200 ml. of hot methanol). The filtrate was concentrated to about 750 ml.; 150 ml. of water were added portionwise thereto; and the resulting solution was allowed to crystallize. A total of 16.1 g. (61%) of (E)-α-acetamido-6-methylindole-3-acrylic acid (mp 204.5-206° C.) was obtained in two crops.

Workup

  1. customAfter removal of the tetrahydrofuran in vacuo and adjustment to pH 3
  2. filtrationfiltered
  3. dissolutionThe filter cake (21.1 g.) was dissolved in 1100 ml
  4. additionof boiling methanol, treated with 2.0 g
  5. waitof charcoal for 10 minutes
  6. filtrationfiltered through a bed of diatomaceous earth (which was washed with 200 ml. of hot methanol)
  7. concentrationThe filtrate was concentrated to about 750 ml
  8. additionof water were added portionwise
  9. customto crystallize

Sources & evidence

ORD record
ord-83fa8ad7ce984e29ad948cca84c171ee
Source dataset
uspto-grants-1979_01
Patent number
US04137404

Reaction notes

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