2-(2-BROMOACETYL)THIOPHENE

white to light yellow crystal powde

2-Bromo-1 -(thiophene-2-yl)ethan-1-one.A solution of bromine (2.53 g, 0.82 mL, 0.0158 mol) in dichloromethane (8 mL) is drop wise added to a solution of 2- acethylthiophene (2.0 g, 1.71 ml_, 0.0158 mol) in same solvent (10 ml_). The reaction mixture is stirred at 25°C per 1 hour and then neutralized with sodium hydrogen carbonate saturated aqueous solution. The organic layer is washed with water and dried. After solvent removal the solid residue is purified by column chromatography (silica gel, ethyl acetate: n-hexane 5:95 as eluent) to give 2-bromo-1-(thiophen-2- yl)ethan-1-one as an oil (2.60 g, 80percent). [Alternative preparation of 1- (thiophen-2-yl)ethan-1-one has been reported recently: Ostrowski, T.; Golankiewicz, B.; De Clercq, E.; Andrei, G.; Snoeck, R. Synthesis and anti-VZV activity of 6-heteroaryl derivatives of tricyclic acyclovir and 9- {[cis-1 \2'-bis(hydroxymethyl)cycloprop-1 '-yl]methyl}guanine analogues. Eur. J. Med. Chem. 2009, 44, 3313-3317].1. General procedure: A mixture of substituted arylethanones 14a-i (10 mmol), N-bromosuccinimide (1.4 g, 12 mmol) and p-toluenesulphonic acid (2.8 g, 15 mmol) in acetonitrile (50 mL) was stirred at 85 °C for 4 h. After completion of reaction (indicated by TLC), the reaction mass was allowed to reach ambient temperature and evaporated excess of acetonitrile under reduced pressure. The residue so obtained was mixed in water, extracted with ethyl acetate (2 × 50 mL). The organic layer was dried over anhydrous NaTo a solution of 2-acetylthiophene (0.310 g, 2.46 mmol) in 33percent of HBr in acetic acid (5.0 mL) was added phenyltrimethylammonium tribromide (0.970 g, 2.58 mmol) at room temperature. a) a) Step 1 : Synthesis of 2-bromo- 1 -(thiophen-2-yl)ethan- 1 -one: [0257] To the stirred solution of l-(thiophen-2-yl)ethan-l-one (10 g, 68.9 mmol) in 110 ml of MeOH at 0°C was added Bromine (2.8 ml, 17.7 mmol) (dropwise addition), stirred for about 30 minutes and stirred for about 2 hours at room temperature. After completion of the reaction (monitored by TLC), the reaction mixture was concentrated and the crude product was dissolved in n-hexane and stirred for about 30 minutes. The obtained solid was filtered and washed with n-hexane then dried and proceeded for next step (wt: 14. Og).

Molecular Weight:205.07
XLogP3:2
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:2
Exact Mass:203.92445
Monoisotopic Mass:203.92445
Topological Polar Surface Area:45.3
Heavy Atom Count:9
Complexity:116
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes