Methyl 6-bromohexanoate

Clear colorless to pale yellow liquid

1. To a solution 6-bromohexanoic acid (10 g, 50 mmol) in MeOH was added few drops of concentrated HSynthesis of Methyl 6-bromohexanoate [0064] Add 6-bromohexanoic acid (4.1 g, 21.1 mmol) into 100 mL absolute methanol solution and then slowly drop 30 mL thionyl chloride into the solution with an ice bath. Stir the solution at room temperature overnight, concentrate the solution and add chloroform to dissolve. After suction filtration, take and concentrate the filtrate to get the product methyl 6-bromohexanoate (4.4 g, 100percent). Compound Data of the Product: [0065] IR (neat) v 11739 (CO) cmTo a stirred solution of 6-bromohexanoic acid 24 (5.00 g, 25.6 mmol) in methanol (75 mL) at 0 °C, thionyl chloride (1.86 mL, 25.6 mmol) was added dropwise. The mixture was warmed to room temperature and stirred for 24 h. The solvent wasremoved in vacuo and the residue was dissolved in ethyl acetate (20 mL), washedwith water (2 x 10 mL), sat. NaHCO3 (10 mL), brine (10 mL) and dried (MgSO4).The solvent was removed in vacuo to give the title product 23 (5.13 g, 96°h) as ayellow oil which was used without further purification. 1H NMR (300 MHz; CDCI3)1.42-1.52 (2H, m, CH2), 1.56-1.66 (2H, m, CH2), 1.85-1.90 (2H, m, CH2), 2.33(2H, t, J = 3.0 Hz, CH2), 3.41 (2H, t, J = 6.0 Hz, CH2), 3.67 (3H, s, CH3). The 1H values are in agreement with literature.56-Bromohexanoic acid methyl ester (27a). To a solution of acetyl chloride (1. 0 mL, 14 mmol) in methanol (150 mL) at 0°C was added a solution of 6-bromohexanoic acid (10.0 g, 51 mmol) in methanol (50 mL). The mixture was heated at reflux for 2 hours, then allowed to cool down to room temperature and concentrated under reduced pressure. The residue was dissolved in ethyl acetate (150 mL) and washed consecutively with saturated aqueous sodium hydrogen carbonate (2 x 50 mL), distilled water (50 mL), and brine (50 mL). The organic layer was dried over anhydrous MgS04, filtered and concentrated under reduced pressure to give the title compound (10.3 g, 96percent) as a colourless oil.6-bromohexanoic acid 18 (4.886 g, 25.100 mmol) was dissolvedin methanol (75 mL). To this solution, Conc. H2SO4 (0.3 mL) was added and reaction mixture refluxed for 8 h. Then solvent evaporatedand residue was dissolved in ethyl acetate (200 mL). Theorganic part was then washed with saturated solution of NaHCO3(50 mL 3), dried and evaporated to give pure ester compound(4.626 g, 22.200 mmol). For making Wittig salt, bromo-estercompound was dissolved in dry CH3CN (70 mL) followed by additiontriphenylphosphine (7.000 g, 26.600 mmol). The reactionmixturewas then refluxed for 36 h. After that solvent evaporated togive gummy residue which was washed with hexanes (20 mL 3)to give compound 19.Example 15a; General Procedure for the Esterification of Bromoalkanoic Acids (I); Appropriate bromo alkanoic acid (1 equiv) was dissolved in methanol and a catalytic amount of conc.HStep 1 General procedure: Typical procedure: After refluxing the mixture of 4a (7.64g, 45.7mmol), methanol (78.4mL), and conc. sulfuric acid (0.77mL) for 16h under a dry argon atmosphere, it was cooled to room temperature. Then, aqueous solution of sodium bicarbonate (78mL) was added to the reaction mixture and the crude product was extracted with ethyl acetate. After washing the combined organic layer with sodium bicarbonate aqueous solution, water, and brine, it was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure. The residue was purified by silica gel chromatography eluted with a mixed solvent of chloroform/methanol (10/1v/v). The fraction with an R

Molecular Weight:209.08
XLogP3:1.9
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:6
Exact Mass:208.00989
Monoisotopic Mass:208.00989
Topological Polar Surface Area:26.3
Heavy Atom Count:10
Complexity:93.6
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes