2-CHLORO-1,3-THIAZOLE-5-CARBALDEHYDE synthesis
- Product Name:2-CHLORO-1,3-THIAZOLE-5-CARBALDEHYDE
- CAS Number:95453-58-0
- Molecular formula:C4H2ClNOS
- Molecular Weight:147.58
3034-52-4
109-94-4
95453-58-0
General procedure: n-Butyl lithium (n-BuLi, 320 mL, 0.8 mol) was slowly added dropwise to a stirred solution of anhydrous THF (1000 mL) of 2-chlorothiazole (80 g) at -78 °C for 1 hour. Maintaining the reaction temperature at -78 °C, ethyl formate (74 g) was slowly added dropwise to the above solution, and the reaction continued to be stirred for 1 hour after the dropwise addition was completed. Saturated ammonium chloride (NH4Cl) solution was added to the reaction mixture and stirred for 30 minutes. Subsequently, the reaction mixture was diluted with ethyl acetate. The aqueous phase was separated and extracted with ethyl acetate. The organic phases were combined, washed sequentially with water and saturated brine and dried over anhydrous sodium sulfate. The organic phase was concentrated under reduced pressure to give the crude product. The crude product was purified by recrystallization from hexane/ethyl acetate mixed solvent to give 2-chloro-1,3-thiazole-5-carbaldehyde (72 g, yield: 73%). The product was characterized by 1H NMR (400 MHz, CDCl3): δ 9.96 (s, 1H), 8.21 (s, 1H).
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95453-58-0
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Yield: 73%
Reaction Conditions:
Stage #1:2-chlorothiazole with n-butyllithium in tetrahydrofuran at -78; for 1 h;
Stage #2:formic acid ethyl ester in tetrahydrofuran at -78; for 1 h;
Steps:
11
To a stirred solution of 2-chlorothiazole E-1 (80 g) in anhydrous THF (1000 ml.) was added n- BuLi (320 ml_, 0.8 mol) drop wise at -78 °C for one hour. Ethyl formate (74 g) was added dropwise to the solution at -78 °C, and stirred for one additional hour. Saturated NH4CI was added to the reaction mixture and stirred for 30 min, then diluted with ethyl acetate. The aqueous phase was extracted with ethyl acetate. The organic phase was washed and dried, then concentrated to give the crude product, which was purified by re-crystallized with hexane/ethyl acetate to give 2-chlorothiazole-5-carbaldehyde E-2 (72 g yield: 73 %,); 1 H NMR (400 MHz, CDCI3): δ ppm 9.96 (s., 1 H), 8.21 (s, 1 H).
References:
BASF SE;DICKHAUT, Joachim;NARINE, Arun;VON DEYN, Wolfgang;KOLLER, Raffael;WACH, Jean-Yves;VYAS, Devendra;ADISECHAN, Ashokkumar;SHINDE, Harish WO2016/55431, 2016, A1 Location in patent:Page/Page column 75
3034-52-4
234 suppliers
$12.00/5g
95453-58-0
151 suppliers
$8.00/250mg