Phenylmethyl 4-bromobutanoate

To a solution of 4-bromobutyryl chloride (Aldrich Chemical Company, Wisconsin), (10.27 g, 55.4 mmol) in 100 mL of dichloromethane was added benzyl alcohol (Aldrich Chemical Company, Wisconsin), (6.29 g, 58.1 mmol), followed by potassium carbonate (8.3 g, 60 mmol) in four portions. After 2 hours, water was added, and the layers were separated. The organic layer was washed with water, brine, and dried over magnesium sulfate. Evaporation of the solvent gave the title compound (11.87 g, 83percent yield) as a colorless oil: [00140] Benzyl alcohol (3.1 ml_, 30 mmol) was added to a solution of Compound 1 (3.47 ml_, 30 mmol) and 4-dimethylaminopyridine (732 mg, 6 mmol) in dichloromethane (100 ml_). The reaction was stirred for 2 hours at room temperature then quenched with 1 M HCI (100 ml_). The organic phase was washed once more with 1 M HCI (100 ml_), dried over MgS04, filtered, dried by rotary evaporation and was dried under vacuum to yield Compound 2 as a colorless oil (6.29 g, 24.5 mmol, 82percent).General procedure: General Procedure for Benzyl Protection of the Bromo-Acid (1c, 1d) [0103] Diisopropylcarbodiimide (DIC) (3.59 mmol, 1.3 eq) was added to a mixture of the bromo-acid (4-bromobutyric acid or 5-bromovaleric acid) (2.76 mmol, 1 eq) and DPTS (3.04 mmol, 1.1 eq) in dry DCM (30 mL) and was allowed to react for 2 hours at room temperature. Benzyl alcohol (4.14 mmol, 1.5 eq) was added and allowed to react overnight. The reaction was washed water and brine, and the DCM was removed by evaporation. Hexanes was added and the resulting white precipitate was removed by filtration. The hexanes was removed from the filtrate by evaporation resulting in an oil which was purified by silica gel chromatography (Hexanes/Ethyl Acetate 3.5/1). Benzyl 4-bromobutyrate (1c) [0104] 70percent yield [0105] 1H NMR (500 MHz, CDCl3) 2.22 (p 2H), 2.58 (t, 2H), 3.48 (t, 2H), 5.16 (s, 2H), 7.40 (m, 5H) [0106] 13C NMR (125 MHz, CDCl3): 28.0, 32.7, 33.0, 66.7, 128.5, 128.6, 128.9, 136.1, 172.6General procedure: General Procedure for Benzyl Protection of the Bromo-Acid (1c, 1d) [0103] Diisopropylcarbodiimide (DIC) (3.59 mmol, 1.3 eq) was added to a mixture of the bromo-acid (4-bromobutyric acid or 5-bromovaleric acid) (2.76 mmol, 1 eq) and DPTS (3.04 mmol, 1.1 eq) in dry DCM (30 mL) and was allowed to react for 2 hours at room temperature. Benzyl alcohol (4.14 mmol, 1.5 eq) was added and allowed to react overnight. The reaction was washed water and brine, and the DCM was removed by evaporation. Hexanes was added and the resulting white precipitate was removed by filtration. The hexanes was removed from the filtrate by evaporation resulting in an oil which was purified by silica gel chromatography (Hexanes/Ethyl Acetate 3.5/1). Benzyl 4-bromobutyrate (1c) [0104] 70% yield [0105] 1H NMR (500 MHz, CDCl3) 2.22 (p 2H), 2.58 (t, 2H), 3.48 (t, 2H), 5.16 (s, 2H), 7.40 (m, 5H) [0106] 13C NMR (125 MHz, CDCl3): 28.0, 32.7, 33.0, 66.7, 128.5, 128.6, 128.9, 136.1, 172.6To a mixture of 4-bromobutyric acid (1 g), benzyl alcohol (0.65 g) and triphenyl phosphine (1.57 g) in tetrahydrofuran (12 mL) was added diethyl azodicarboxylate (40% toluene solution, 2.88 mL), and the mixture was stirred at room temperature for 3 hours. The reaction mixture was poured into water, and the resulting mixture was extracted with diethyl ether. The extract was washed with water and brine, and dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure, and the residue was purified by column chromatography on silica gel (eluent: n-hexane/ethyl acetate = 20/1) to give the title compound (0.69 g).1H-NMR (CDCl3) delta ppm: 2.15-2.25 (2H, m), 2.56 (2H, t, J=7.1Hz), 3.46 (2H, t, J=6.5Hz), 5.13 (2H, s), 7.25-7.4 (5H, m)Benzyl alcohol (2.84 mL, 27.3 mmol), 4-bromobutanoic acid (5.01 g, 30.0 mmol) and DMAP (0.33 g, 2.73 mmol) were dissolved in methylene chloride (50 mL), added with EDC (6.5 g, 34.1 mmol) under ice cooling and stirred at room temperature for 2.5 hours. The reaction mixture was concentrated under reduced pressure and then dissolved in diethyl ether. The solution was washed sequentially with a saturated sodium hydrogen carbonate aqueous solution, water and a 10% citric acid aqueous solution and dried over anhydrous magnesium sulphate. Following filtration, the solvent was removed by distillation under reduced pressure to obtain the titled compound (6.41 g, 24.9 mmol). 1H-NMR(600MHz, CDCl3)delta(ppm):2.20(quin, J=6.83Hz, 2H), 2.56(t, J=7.15Hz, 2H), 3.46(t, J=6. 51Hz, 2H), 5.13(s, 2H), 7.28-7.42(m, 5H).

Molecular Weight:257.12
XLogP3:3
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:6
Exact Mass:256.00989
Monoisotopic Mass:256.00989
Topological Polar Surface Area:26.3
Heavy Atom Count:14
Complexity:165
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes