Lithium hydroxide, monohydrate → 2-Amino-5-methylthiophene-3-carboxylic acid

HRID 651633Notes

Reaction equation

HRID 651633 reaction equation
C[O:2][C:3]([C:5]1[CH:9]=[C:8]([CH3:10])[S:7][C:6]=1[NH2:11])=[O:4].O[Li].O>CO.O.C1COCC1>[NH2:11][C:6]1[S:7][C:8]([CH3:10])=[CH:9][C:5]=1[C:3]([OH:4])=[O:2]

Participants

4

Reactant 2

HCID 168937Lithium hydroxide, monohydrateHCID 675878Methyl-2-amino-5-methyl-3-thiophenecarboxylate

Product 1

HCID 219315912-Amino-5-methylthiophene-3-carboxylic acidYield 95%

Reagents, catalysts & solvents 1

HCID 21892291Methanol tetrahydrofuran waterSolvent

Conditions

Temperature
50 °C

Procedure

To a solution of 2-amino-5-methylthiophene-3-carboxylic acid methyl ester (13.7 g, 80 mmol) in MeOH/H2O/THF (400 mL, 1:1:1) is added LiOH.H2O (16 g, 400 mmol). The solution is heated to 50° C. After 4 hours, the solution is concentrated. The resulting residue is dissolved in water. The pH of the solution is adjusted to between 5-6 using 1 N HCl. The precipitate is collected by filtration, washed with a small amount of water and is dried under vacuum. The title compound (12 g, 76 mmol) is obtained as a yellow solid.

Workup

  1. concentrationthe solution is concentrated
  2. dissolutionThe resulting residue is dissolved in water
  3. filtrationThe precipitate is collected by filtration
  4. washwashed with a small amount of water
  5. customis dried under vacuum

Sources & evidence

ORD record
ord-8aecac84976d4b2485c473f31fd5bfc0
Source dataset
uspto-grants-2001_08
Patent number
US06281227B1

Reaction notes

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