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

HRID 1015612Notes

Reaction equation

HRID 1015612 reaction equation
C[O:2][C:3]([C:5]1[S:6][C:7]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=[CH:8][C:9]=1[NH2:10])=[O:4].O[Li].O>C1COCC1.CO.O>[NH2:10][C:9]1[CH:8]=[C:7]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)[S:6][C:5]=1[C:3]([OH:4])=[O:2]

Participants

4

Reactant 2

HCID 168937Lithium hydroxide, monohydrateHCID 700562Methyl 3-amino-5-phenylthiophene-2-carboxylate

Product 1

HCID 198432823-Amino-5-phenylthiophene-2-carboxylic acidYield 88.2%

Reagents, catalysts & solvents 1

HCID 21892291Methanol tetrahydrofuran waterSolvent

Conditions

Temperature
85 °C

Procedure

To a suspension of 3-Amino-5-phenyl-thiophene-2-carboxylic acid methyl ester (5 g, 21.459 mmol) in a mixture of THF:MeOH:H2O (3:2:1, 75 mL), 1N aqueous solution of LiOH.H2O (64 mL, 64.378 mmol) was added. The reaction mixture was stirred at 85° C. (external temperature) for 4 h. Solvents were removed under reduced pressure and the residue was partitioned between water and ethyl acetate. The water layer was separated and acidified with 1N HCl solution and then ethyl acetate was added to it. The organic phase was separated, dried (Na2SO4) and concentrated to obtain 3-Amino-5-phenyl-thiophene-2-carboxylic acid (4.15 g, 88%) as a yellowish solid. 1H NMR (DMSO-D6, 400 MHz): 7.59 (d, 2H), 7.40 (m, 3H), 6.92 (s, 1H).

Workup

  1. additionwas added
  2. customSolvents were removed under reduced pressure
  3. customthe residue was partitioned between water and ethyl acetate
  4. customThe water layer was separated
  5. additionethyl acetate was added to it
  6. customThe organic phase was separated
  7. dry with materialdried (Na2SO4)
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-97197f080c6d4113b0446660de63255a
Source dataset
uspto-grants-2011_07
Patent number
US07985769B2

Reaction notes

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