ChemicalBook CAS DataBase List Methyl 4-oxotetrahydrothiophene-3-carboxylate

Methyl 4-oxotetrahydrothiophene-3-carboxylate synthesis

5synthesis methods

Product Name:Methyl 4-oxotetrahydrothiophene-3-carboxylate
CAS Number:2689-68-1
Molecular formula:C6H8O3S
Molecular Weight:160.19

2,3,4,5-Tetrahydro-4-oxo-3-thiophene carboxylic acid, methyl ester (L75a): 25.3 g (1.1 mol) of sodium were implemented in 190 mL abs. methanol to methylate. To methylate solution 70 g (0.360 mol) (L74) was added dropwise at the boiling point and the reaction mixture was heated for 45 min under reflux. The cooling mixture was poured onto a mixture of 500 mL ice and 300 mL water, acidified with 100 mL conc. HCl and the oily precipitating product was brought to crystallize under cooling with ice/sodium chloride bath. The crystals were sucked off, resumed in 100 mL methylene chloride and dried over sodium sulfate and evaporated. There were obtained 16.7 g of pale beige crystals. The aqueous phase was extracted three times with 100 mL of methylene chloride, the organic phase dried over sodium sulfate and evaporated. 30 g of crystalline product Methyl 4-oxotetrahydrothiophene-3-carboxylate was obtained. Yield: 46.7 g of light beige crystals (81 % of theory). mp 29-31 degC. TLC: Bz:MeOH:AcOH = 45:8:4, Rf = 0.75.

Methyl 4-oxotetrahydrothiophene-3-carboxylate synthesis

7400-45-5
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Methyl 4-oxotetrahydrothiophene-3-carboxylate

2689-68-1
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$20.00/250 mg

Yield:2689-68-1 80%

Reaction Conditions:

with pyridine in toluene at 80; for 2.5 h;

Steps:

Synthesis of 3-keto-4-carbomethoxy-2,5-tetrahydrothiophene (0)
Pyridine (0.2 mol) and toluene (500 mL) was stirred under 80°C for 10 min, then (II) (0.2 mol) was added to the solution and it was maintained at the temperature 80°C for 1h. In addition of (II) (0.2 mol) was added to the mixture in 20 min and the solution was refluxed for 1h. When cooled down to the room temperature, the samples adjusted to pH 7 with 0.5M hydrochloric acid in the ice-sodium chloride cold bath, and the toluene layer were separated. Residual solution was extracted based on ether (3*50mL),and combined with toluene layer. The mixture was evaporated to dryness in a vacuum, recrystallization from petroleum ether-anhydrous ethanol gave 38.4g of yellowish-white crystals (compound 0),Yield: 80%; mp : 36~38 C; 1H NMR(CDCl3) δ:3.75 (t,2H, J=3 Hz), 3.78 (s, 3H), 3.81 (t, 2H, J=3 H z), 10.93 (s,1H); 13C NMR (CDCl3) δ: 31.40, 38.03, 51.63, 99.21,169.55, 172.43 ppm; ESI-MS: m/z183.01 (M+Na+,100%).

References:

Tan, Chunbin;Liu, Xiaoling;Du, Hongfei [Revue Roumaine de Chimie,2019,vol. 64,# 3,p. 271 - 276]

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7400-45-5
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$35.39/1g