ChemicalBook CAS DataBase List ETHYL 2-CHLOROTHIAZOLE-5-CARBOXYLATE

ETHYL 2-CHLOROTHIAZOLE-5-CARBOXYLATE synthesis

4synthesis methods

Product Name:ETHYL 2-CHLOROTHIAZOLE-5-CARBOXYLATE
CAS Number:81449-93-6
Molecular formula:C6H6ClNO2S
Molecular Weight:191.64

32955-21-8

81449-93-6

The general procedure for the synthesis of ethyl 2-chloro-1,3-thiazole-5-carboxylate from ethyl 2-aminothiazole-5-carboxylate was as follows: ethyl 2-aminothiazole-5-carboxylate (1.0 g, 6.35 mmol) was dissolved in a solvent mixture of acetonitrile (10 mL) and tetrahydrofuran (10 mL) at 23 °C. The solution was then slowly added to a mixture of acetonitrile (10 mL) and tetrahydrofuran (10 mL) containing butyl nitrite (1.3 mL, 9.52 mmol) and cuprous chloride (1.0 g, 7.6 mmol). The reaction mixture was to be heated at 65°C until thin layer chromatography (TLC) analysis (unfolding agent was 40% ethyl acetate-hexane) showed complete consumption of the raw materials. After completion of the reaction, the mixture was cooled to room temperature and extracted by partitioning between water and ethyl acetate. The organic layer was collected, concentrated under reduced pressure and finally purified by fast silica gel column chromatography with 20% ethyl acetate-hexane as eluent to afford the target product ethyl 2-chloro-1,3-thiazole-5-carboxylate (0.49 g, 40% yield).

32955-21-8 Synthesis

32955-21-8
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$7.00/1g

81449-93-6
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$19.00/1g

Yield: 40%

Reaction Conditions:

with tert.-butylnitrite;copper dichloride in tetrahydrofuran;acetonitrile at 23 - 65;

Steps:

3 Example 3: The synthesis of compound (2)
[0097] At 23°C, a solution of ethyl 2-aminothiazole-4-formate (1.0 g, 6.35 mmol) in acetonitrile (10 mL) and tetrahydrofuran(10 mL) is added to a solution (10 mL) of t-butyl nitrite (1.3 mL, 9.52 mmol) and cuprous chloride (1.0 g, 7.6mmol) in acetonitrile (10 mL) and tetrahydrofuran (10 mL). The reaction mixture is required to be heated at 65 °C untilcomplete consumption of the starting materials as shown by thin-layer chromatography (40% ethyl acetate-hexane).Then, the mixture is cooled to room temperature and partitioned between water and ethyl acetate. The organic layer isconcentrated under vacuum and purified by flash silica gel column chromatography eluted with 20% ethyl acetate-hexaneto give ethyl 2-chloro-thiazole-4-formate (compound (2-2)) (0.49 g, 40%).

References:

Hangzhou Bensheng Pharmaceutical Co., Ltd.;XU, Rongzhen;XIE, Fuwen;LAI, Hongxi;RONG, Frank EP2615092, 2013, A1 Location in patent:Paragraph 0095; 0097

64-17-5 Synthesis