Sodium Hydroxide → 4-oxo-5,6-dihydro-4H-cyclopenta[b]thiophene-2-carboxylic acid

HRID 1907794Notes

Reaction equation

HRID 1907794 reaction equation
[OH-].[Na+].C(N(CC)CC)C.CN1[C:15](=[O:16])/[C:14](=[CH:17]/[CH:18]2[C:22](=[O:23])[CH2:21][CH2:20][C:19]2=O)/[S:13]C1=S.[OH:26]P([O-])(O)=O.[K+]>O>[O:23]=[C:22]1[C:18]2[CH:17]=[C:14]([C:15]([OH:16])=[O:26])[S:13][C:19]=2[CH2:20][CH2:21]1

Participants

5

Reactant 3

HCID 14798Sodium HydroxideHCID 516951Monobasic potassium phosphateHCID 86659960HCID 86659960, compound

Product 1

HCID 585400924-oxo-5,6-dihydro-4H-cyclopenta[b]thiophene-2-carboxylic acidYield 37%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

In a 500-mL round-bottomed flask equipped with a magnetic stirrer and reflux condenser, was charged with sodium hydroxide (3.34 g, 83.6 mmol) and water (65 mL). The solution was degassed with nitrogen for 15 min. 4 (7.19 g, 20.2 mmol) was added and the mixture was stirred at room temperature for 3 h. After this time, 1 M aqueous potassium phosphate monobasic was added to adjust the pH of the reaction mixture to 8.0, followed by water (200 mL). After heating at 50° C. for 16 h, the water was evaporated to 50 mL under reduced pressure, and 12 N hydrochloric acid was added to adjust the pH to 2.8 (pH meter). The resulting precipitate was collected by vacuum filtration, washed with water (5 mL) and dried for 16 h under vacuum at 50° C. to afford 5 in 37% yield (1.37 g) as a green solid: mp 195-196° C.; 1H NMR (500 MHz, DMSO-d6) δ 13.30 (br s, 1H), 7.64 (s, 1H), 3.23 (t, 2H, J=5.5 Hz), 2.76 (t, 2H, J=5.5 Hz); MS (APCI+) m/z 183.2 (M+H).

Workup

  1. customIn a 500-mL round-bottomed flask equipped with a magnetic stirrer
  2. temperaturereflux condenser
  3. customThe solution was degassed with nitrogen for 15 min
  4. temperatureAfter heating at 50° C. for 16 h
  5. customthe water was evaporated to 50 mL under reduced pressure, and 12 N hydrochloric acid
  6. additionwas added
  7. filtrationThe resulting precipitate was collected by vacuum filtration
  8. washwashed with water (5 mL)
  9. customdried for 16 h under vacuum at 50° C.
  10. customto afford 5 in 37% yield (1.37 g) as a green solid

Sources & evidence

ORD record
ord-6fd48730be8d493b9948ea378830bcae
Source dataset
uspto-grants-2013_12
Patent number
US08598174B2

Reaction notes

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