反应详情

To a solution of 5-bromo-2-chlorobenzoic acid 45 (1.22 g) in a mixture of tetrahydrofuran (20 ml)-toluene (20 ml) was added dropwise n-butyl lithium (2.44 M hexane solution, 4.26 ml) at −78° C. under argon atmosphere. The mixture was stirred at −78° C. for 30 minutes, and added dropwise thereto was a solution of 2,3,4,6-tetra-O-benzyl-β-D-glucolactone 46 (2.16 g) in toluene (10 ml), and the mixture was further stirred at the same temperature for 2 hours. To the mixture was added a saturated aqueous ammonium chloride solution, and the mixture was warmed to room temperature. The reaction mixture was made acidic by addition of 10% aqueous hydrochloric acid solution, and extracted with ethyl acetate. The extract was washed with brine, and dried over magnesium sulfate. The solvent was evaporated under reduced pressure to give a crude compound 47 as oil, which was used in the subsequent step without further purification. (2) The above crude compound 47 was dissolved in dichloromethane (30 ml), and thereto were added dropwise triisopropylsilane (2.46 ml) and boron trifluoride•diethyl ether complex (1.52 ml) at −78° C. Subsequently, the mixture was stirred at 0° C. for one hour, and added thereto was a saturated aqueous sodium hydrogen carbonate solution, and the mixture was further stirred for 20 minutes. The reaction mixture was made acidic by addition of 10% aqueous hydrochloric acid solution, and extracted with ethyl acetate. The extract was washed with brine, and dried over magnesium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel chromatography (chloroform:methanol=100:1-50:1) to give a compound 48 (1.41 g) as oil. (3) The compound 48 (1.41 g) was dissolved in dichloromethane (10 ml), and added thereto was oxalyl chloride (2 ml). The mixture was stirred at room temperature for 3 hours. The solvent was evaporated under reduced pressure to give a corresponding acid chloride. The compound was dissolved in chloroform (10 ml), and added dropwise to a solution of N,O-dimethylhydroxyamine hydrochloride (390 mg) and triethyl amine (1.12 ml) in chloroform (10 ml) at 0° C. The mixture was stirred at room temperature overnight, and the reaction mixture was washed successively with 10% aqueous hydrochloric acid solution, water, a saturated aqueous sodium hydrogen carbonate solution and brine. The mixture was dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=4:1-2:1) to give a compound 49 (784 mg) as pale yellow oil. APCI-Mass m/Z 739/741 (M+NH4). (4) The compound 49 (1.22 g) was dissolved in tetrahydrofuran (20 ml), and the mixture was cooled to −78° C. under argon atmosphere. To the mixture was added dropwise diisobutylaluminum hydride (1.0 M toluene solution, 4.2 ml), and the mixture was stirred at the same temperature for 3 hours. Added thereto was 10% aqueous hydrochloric acid solution, and the mixture was extracted with ethyl acetate. The extract was washed successively with a saturated aqueous sodium hydrogen carbonate solution and brine. The extract was dried over magnesium sulfate and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=9:1) to give a compound 50 (771 mg) as pale yellow oil. APCI-Mass m/Z 680/682 (M+NH4). (5) 2,5-dibromothiophene 51 (1.31 g) was dissolved in tetrahydrofuran (30 ml) and the mixture was cooled to −78° C. under argon atmosphere. To the mixture was added dropwise n-butyl lithium (2.59 M hexane solution, 2.01 ml), and the mixture was stirred at the same temperature for 30 minutes. Added dropwise thereto was a solution of the above compound 50 (2.40 g) in tetrahydrofuran (15 ml), and the mixture was stirred at −78° C. for 2 hours. Added thereto was a saturated aqueous ammonium chloride solution, and the mixture was extracted with ethyl acetate and washed with brine. The extract was dried over magnesium sulfate and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=9:1-4:1) to give a compound 52 (2.62 mg) as pale brown oil. APCI-Mass m/Z 842/844 (M+NH4). (6) The compound 52 was treated in a manner similar to Example 3-(2) to give 1-(2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl)-3-(5-bromo-2-thienylmethyl)-4-chlorobenzene 53 as a pale yellow solid. APCI-Mass m/Z 826/828 (M+NH4). (7) A mixed solution of the above 1-(2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl)-3-(5-bromo-2-thienylmethyl)-4-chlorobenzene 53 (200 mg), tri-n-butyl(2-pyrimidinyl)tin 54 (137 mg) and bis(triphenylphosphine)palladium(II)dichloride (9 mg) in N-methyl-2-pyrrolidinone (5 ml) was stirred at 100° C. four 7 hours under argon atmosphere. The mixture was cooled to room temperature, and water was added thereto, and the mixture was extracted with ethyl acetate. The extract was washed with water and subsequently with brine, and dried over magnesium sulfate. The solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=4:1-2:1) to give 1-(2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl)-4-chloro-3-(5-(2-pyrimidinyl)-2-thienylmethyl)benzene 55 (93 mg) as pale brown oil. APCI-Mass m/Z 826/828 (M+NH4). (8) To a solution of the above 1-(2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl)-4-chloro-3-(5-(2-pyrimidinyl)-2-thienylmethyl)benzene 55 (90 mg) in ethanethiol (1.5 ml) was added boron trifluoride•ether complex (0.42 ml) at 0° C., and the mixture was stirred at room temperature overnight. The mixture was cooled again to 0° C., and added thereto were a saturated aqueous sodium hydrogen carbonate solution and an aqueous sodium thiosulfate solution. The mixture was extracted with ethyl acetate and tetrahydrofuran, and the extract was dried over magnesium sulfate. The solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (chloroform:methanol=19:1-9:1) to give the desired 1-(β-D-glucopyranosyl)-4-chloro-3-(5-(2-pyrimidinyl)-2-thienylmethyl)benzene 56 (27 mg) as pale yellow powder. APCI-Mass m/Z 449/451 (M+H).

1. temperatureThe mixture was cooled again to 0° C.
2. additionadded
3. extractionThe mixture was extracted with ethyl acetate and tetrahydrofuran
4. dry with materialthe extract was dried over magnesium sulfate
5. customThe solvent was evaporated under reduced pressure
6. customThe residue was purified by silica gel column chromatography (chloroform:methanol=19:1-9:1)