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ChemicalBook CAS DataBase List ETHYL 2-AMINO-5-ETHYLTHIOPHENE-3-CARBOXYLATE
4507-13-5

ETHYL 2-AMINO-5-ETHYLTHIOPHENE-3-CARBOXYLATE synthesis

2synthesis methods
-

Yield: 49%

Reaction Conditions:

Stage #1:sulfur;ethyl 2-cyanoacetate with triethylamine in N,N-dimethyl-formamide at 20; for 0.166667 h;
Stage #2:butyraldehyde in N,N-dimethyl-formamide at 20; for 2 h;

Steps:

1g
Compound 131a. 2-Amino-5-ethyl-thiophene-3-carboxylic acid ethyl ester: Ethyl cyanoacetate (5.0 g, 44.0 mmol, 1.0 eq), sulphur (1.42 g, 44.0 mmol, 1.0 eq), and triethylamine (2.24 g, 22.0 mmol, 0.5 eq) were dissolved in DMF (20 ml) and the reaction stirred at room temperature for 10 minutes. Butyraldehyde (3.19 g, 44.0 mmol, 1.0 eq) was added drop-wise to the reaction mixture, keeping the temperature under 500C. The reaction was then stirred at room temperature for 2 hours then poured into water (80 ml). The resultant solid was isolated by filtration, washed with water (400 ml), dried on the sinter, washed with cyclohexane (200 ml) and dried in vacuo to give the title compound as an orange solid (4.29 g, 21.53, 49%). 1H NMR shows product in >95% purity.

References:

DEVELOGEN AKTIENGESELLSCHAFT WO2006/136402, 2006, A1 Location in patent:Page/Page column 79

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