2-BROMO-1-(1,3-THIAZOL-2-YL)ETHANONE

Step A 10 mmol 2-acetylthiazole added to a 100 mL round bottom flaskAnd 11mmol of N-bromosuccinimide (NBS), Dissolve 35mL of ethyl acetate and add 1g of Amberlyst 15 ion exchange resin as catalyst.The reaction was warmed to 40°C and reacted. After TLC tracks the reaction, The reaction solution was filtered to remove Amberlyst 15 ion exchange resin, and the filtrate was spin-dried.Column chromatography (eluent: petroleum ether/dichloromethane) gave a yellow solid in 50percent yield.(i) To a solution of 1-(thiazol-2-yl)ethan-1-one (0.25 g, 1.97 mmol) in AcOH (5 mL), pyridinium bromide perbromide (0.82 g, 2.57mmol) was added and allowed the mixture to stir at room temperature for 35 hours. After TLCshowed completion, diluted the mixture with EtOAc (20 mL) and washed with water (3 x 10mL). The organic layer was dried over Na2SO4 and concentrated to obtain crude 2-bromo-1-(thiazol-2-yl)ethan-1-one (310 mg, crude), which was used in next step without furtherpurification.n-Butyllithium (24.7 mL, 0.0617 mol, 2.5M in flexane) was added dropwise to a solution of 2-thiazole (5.0 g, 0.059 mol) in anhydrous diethyl ether (48.8 mL) at -78°C. After 15 minutes, ethylbromoacetate (6.84 mL, 0.0617 mol) was added, the cold bath was removed and the solution was allowed to warm to room temperature. The reaction mixture was diluted with ether and water. The organic layer was separated, dried over Na2SO4, filtered and concetrated under reduced pressure. The crude product was suspended in hexanes and heated to reflux for 15 minutes then the product was decanted off leaving the impure oil. This was repeated 5 times to give a white solid with 88 percent yield. ‘H NMR (400 MHz, CDC13) S 8.05 (d, J = 3.0 Hz, 111), 7.77 (d, J = 3.0 Hz, 111), 4.71 (s, 211). ESI-MS (mz): 207.8 [M+Hj+.n-Butyllithium (24.7 mL, 0.0617 mol, 2.5M in Hexane) was added dropwise to a solution of 2-thiazole (5.0 g, 0.059 mol) in anhydrous diethyl ether (48.8 mL) at -78°C. After 15 minutes, ethylbromoacetate (6.84 mL, 0.0617 mol) was added, the cold bath was removed and the solution was allowed to warm to room temperature. The reaction mixture was diluted with ether and water. The organic layer was separated, dried over Na2S04, filtered and concetrated under reduced pressure. The crude product was suspended in hexanes and heated to reflux for 15 minutes then the product was decanted off leaving the impure oil. This was repeated 5 times to give a white solid with (0445) 88 percent yield. H NMR (400 MHz, CDC13) δ 8.05 (d, J (0446) 4.71 (s, 2H). ESI-MS (m/z): 207.8 [M+H]+.n-Butyllithium (24.7 mL, 0.0617 mol, 2.5M in Hexane) was added dropwise to a solution of 2-thiazole (5.0 g, 0.059 mol) in anhydrous diethyl ether (48.8 mL) at -78C. After 15 minutes, ethylbromoacetate (6.84 mL, 0.0617 mol) was added, the cold bath was removed and the solution was allowed to warm to room temperature. The reaction mixture was diluted with ether and water. The organic layer was separated, dried over NaPreparation 2A; 2-Bromoacetylthiazole; Preparation 2A; 2-Bromoacetylthiazole; In a 50 mL round bottom flask were added intermediate VII (384 mg, 2.0 mmol), potassium carbonate (304 mg, 2.2 mmol) and intermediate III (451 mg, 2.2 mmol), acetonitrile (25 mL) as a solvent, and the reaction was stirred at 60 C. Thin layer chromatography was followed to the end of the reaction, cooled to room temperature, and subjected to post-treatment such as column chromatography separation, recrystallization, drying, etc. to obtain intermediate VIII (450 mg), yield 67.2%; white powder; melting point: 224-225C.In a 50 mL round-bottomed flask, add 4-chloromethylene-7-hydroxycoumarin (210 mg, 1.0 mmol), potassium carbonate (152 mg, 1.1 mmol) and bromoacetylthiazole (225 mg, 1.1 mmol), and acetonitrile (25 mL ) As a solvent, the reaction was stirred at 60 C, followed by thin layer chromatography to the end of the reaction, cooled to room temperature, and subjected to post-treatment such as column chromatography separation and drying to obtain intermediate VI (150 mg), yield 44.8%; white solid; melting point : 190-192 C, in which 4-chloromethylene-7-hydroxycoumarin is obtained by resorcinol as a starting material through Pechmann reaction.

Molecular Weight:206.06
XLogP3:1.8
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:2
Exact Mass:204.91970
Monoisotopic Mass:204.91970
Topological Polar Surface Area:58.2
Heavy Atom Count:9
Complexity:120
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes