ChemicalBook CAS DataBase List 1,3-Thiazole-2-carbaldehyde

1,3-Thiazole-2-carbaldehyde synthesis

7synthesis methods

Product Name:1,3-Thiazole-2-carbaldehyde
CAS Number:10200-59-6
Molecular formula:C4H3NOS
Molecular Weight:113.14

3034-53-5

68-12-2

10200-59-6

General procedure for the synthesis of 2-formylthiazole from 2-bromothiazole and N,N-dimethylformamide: An ether (43 mL) solution of 2-bromothiazole (10.00 g, 60.96 mmol) was added dropwise to a cooled solvate over a period of 1 hr at -78°C. Subsequently, 1.6 M butyl lithium (46 mL, 73.5 mmol) in hexane was added. The resulting mixture was stirred at -70 °C for 20 min, and then N,N-dimethylformamide (7.50 mL, 97.5 mmol) was added over 1 h while keeping the temperature below -65 °C. The reaction was carried out at -65 °C. The reaction mixture was warmed to -40°C over 1 hr and stirring was continued at this temperature for 1 hr. The reaction mixture was slowly warmed to 0 °C and quenched with 4 M aqueous hydrochloric acid. The organic and aqueous layers were separated. The organic layer was washed with 4M aqueous hydrochloric acid solution and discarded. The combined aqueous layers were neutralized with potassium carbonate and extracted with ether (3 times). The combined organic extracts were dried over magnesium sulfate, filtered, and the solvent was removed in vacuum to give 2-formylthiazole (6.88 g, 99% yield) as a brown oil, which did not require further purification.

3034-53-5 Synthesis

3034-53-5
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10200-59-6
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Yield:10200-59-6 4.95 g (93.9%)

Reaction Conditions:

with n-butyllithium in hexane;N,N-dimethyl-formamide

Steps:

1.a EXAMPLE 1
(a) To a solution of n-butyllithium (3.14 g, 49 mmol, 2M in hexane) in 80 ml of ether under argon at -78° C. was added dropwise a solution of 2-bromothiazole (7.8 g, 47.55 mmol) in 1 h. The mixture was stirred at -78° C. for 1 h, and then a solution of DMF (3.48 g, 47.55 mmol) in ether was added. The mixture was stirred for 1 h at -78° C., then at -15° C. for 18 h. The reaction mixture was then extracted with 4N HCl (4*20 ml), the aqueous layers were combined, cooled in an ice-bath, and neutralized with sodium bicarbonate. The aqueous layer was extracted with ether (4*35 ml), the organic layer was dried over sodium sulfate and concentrated in vacuo to afford 4.95 g (93.9%) of 2-thiazolylcarboxaldehyde.

References:

Sterling Winthrop Inc. US5569655, 1996, A

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