Reaction #42387

Reaction equation

methyl 5-{[butyl(methyl)amino]methyl}thiophene-2-carboxylate

lithium hydroxide monohydrate

→

title compound

5-{[Butyl(methyl)amino]methyl}thiophene-2-carboxylic acid

Solvents

dioxane methanol water

Conditions

Workup

1. 1
   ConcentrationThe reaction mixture is concentrated under reduced pressure
2. 2
   Otherthe solid residue partitioned between ethyl acetate and water The aqueous phase
3. 3
   Extractionextracted several times with 3:1 chloroform/2-propanol
4. 4
   WashThe combined organic phase is washed with water, and brine
5. 5
   Dryingdried (sodium sulfate)
6. 6
   Filtrationfiltered
7. 7
   Concentrationconcentrated under reduced pressure

Procedure

To a solution of methyl 5-{[butyl(methyl)amino]methyl}thiophene-2-carboxylate (280 mg, 1.16 mmol) in 2:1:1 dioxane/methanol/water (8.0 mL) is added lithium hydroxide monohydrate (146 mg, 3.38 mmol) and the reaction mixture stirred at room temperature overnight. The reaction mixture is concentrated under reduced pressure and the solid residue partitioned between ethyl acetate and water The aqueous phase is acidified to pH 1 with 1 N hydrochloric acid and extracted several times with 3:1 chloroform/2-propanol. The combined organic phase is washed with water, and brine, dried (sodium sulfate), filtered, and concentrated under reduced pressure to provide the title compound in pure form. 1H NMR (300 MHz, CD3OD) δ 7.75 (d, J=4 Hz, 1H), 7.41 (d, J=4 Hz, 1H), 4.63 (s, 2H), 3.20-3.14 (m, 2H), 2.85 (s, 3H), 1.82-1.72 (m, 2H), 1.42 (tq, J 8, 7 Hz, 2H), 0.99 (t, J=7 Hz, 3H).

Source