Methyl 2-bromothiophene-3-carboxylate

Treat a solution of 2-bromo-3-thiophenecarboxylic acid (10.1 g, 49 mmol) in MeOH (100 mL) with sulfuric acid (2.5 mL, 45 mmol). Heat the reaction to reflux overnight. Concentrate the mixture under reduced pressure to remove the organic solvent and pour the resulting mixture into ice cold water. Extract the cold solution with EtOAc. Wash the combined organic extracts with water followed by a saturated aqueous sodium bicarbonate solution. Dry the organic solution over anhydrous sodium sulfate, filter and concentrate the filtrate under reduced pressure to give the title compound 10.77 g (100percent). 12.1 g (58.4 mmol) of Compound 1, 10 mL of concentrated sulfuric acid and 250 mL of methanol were placed in a reaction vessel and refluxed for 6 hours. The obtained reaction solution was poured into water and extracted with toluene. The liquid obtained by concentrating the obtained toluene solution was purified using a silica gel column to obtain Compound 2. [ The yield was 12.8 g and the yield was 99percent.Process 10 2-bromo-3-thiophene carboxylic acid (1.0 eq, 12.56 g, 60.66 mmol) was suspended in CH2-bromo-3-thiophene carboxylic acid (1.0 eq, 12.56 g, 60.66 mmol) was suspended in CHTreat a solution of 2-bromothiophene-3--carboxylic acid (65 g, 314 mmol) inMeOH (500 rnL) with thionyl chloride (1 3.5 g, i 13 mmoi) at room temperature. Stir the mixture for 30 minutes at room temperature and then heat the mixture to reflux for three hours. Allow the mixture to cool while stirring overnight. Concentrate the reaction mixture under reduced pressure. Add EtOAc and wash the resulting organic solution with saturated aqueous sodium bicarbonate. Separate the layers and back extract the aqueoussolution with additional EtOAc. Combine the organic solutions and thy over anhydroussodium sulfate. Filter the solution and concentrate the filtrate under reduced pressure.Purify the residue by silica gel column chromatography by loading the product onto a 220g pre-coiumn and eluting the pre-column onto a 330 g column with a gradient from 10-25percent EtOAc in DCM. Combine the appropriate fractions and concentrate under reducepressure to give the title compound 71 g. Use the material without further purification.1H NMR (400.15 MHz, DMSO-d6) ö 7.36-7.34 (d, J5.6 Hz, 1H), 7.22-7, 20 (d, J5.6 Hz, 1H), 3.87 (s, 3H).Acetonitrile (30 mL) to

Molecular Weight:221.07
XLogP3:2.5
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:2
Exact Mass:219.91936
Monoisotopic Mass:219.91936
Topological Polar Surface Area:54.5
Heavy Atom Count:10
Complexity:140
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes