methyl 2-(bromomethyl)but-2-enoate

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: In a manner to that of S. E. Drews, D. Emsley, et al., in J. Chem. Soc., Perkin Transaction I, pp. 2079 and 2079 (1982), an ice cooled solution of methyl acrylate (IV) (8.6 g) in conc. HBr (16.5 ml) is mixed dropwise with acetaldehyde (V) (4.4 g) and then conc. sulfuric acid (15 ml). After stirring overnight, the reaction mixture is extracted thrice with ether. The extract is washed with saturated saline, dried over MgSO4, and concentrated. The resulting residue is distilled under reduced pressure to give methyl 2-bromomethyl-2-butenoate (III) (8.59 g). 83°~85° C./10 mmHg. the reaction mixture is extracted thrice with ether The extract is washed with saturated saline dried over MgSO4 concentrated The resulting residue is distilled under reduced pressure

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: In a manner to that of S. E. Drews, D. Emsley, et al., in J. Chem. Soc., Perkin Transaction I, pp. 2079 and 2079 (1982), an ice cooled solution of methyl acrylate (IV) (8.6 g) in conc. HBr (16.5 ml) is mixed dropwise with acetaldehyde (V) (4.4 g) and then conc. sulfuric acid (15 ml). After stirring overnight, the reaction mixture is extracted thrice with ether. The extract is washed with saturated saline, dried over MgSO4, and concentrated. The resulting residue is distilled under reduced pressure to give methyl 2-bromomethyl-2-butenoate (III) (8.59 g). 83°~85° C./10 mmHg. the reaction mixture is extracted thrice with ether The extract is washed with saturated saline dried over MgSO4 concentrated The resulting residue is distilled under reduced pressure

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 8.0 g (46 mmoles) of N-bromosuccinimide were dissolved in 60 ml of dry dichloromethane and were cooled to 0° C. To the mixture were added drop by drop 4 ml (50 mmoles) of dimethyl sulphide dissolved in 40 ml of chloromethane. The mixture was stirred for 10 minutes at 0° C. At the end of that time 5.46 (42 mmoles) of a solution of methyl 3-hydroxy-2-methylidene-butanoate in 40 ml of dichloromethane were slowly added to it. The resulting suspension was stirred for 24 hours at room temperature until a transparent solution was obtained. To this mixture was added n-hexane (100 ml) and it was poured into a separating funnel containing 200 ml of a saturated solution of sodium chloride and ice. The organic phase was washed with 100 ml of a saturated solution of sodium chloride. The aqueous phases were extracted with diethyl ether (2×100 ml), they were washed with water (3×100 ml) and they were dried over anhydrous sodium sulphate. They were vacuum concentrated giving 7.45 g (92% yield) of a syrupy liquid of methyl 2-bromomethyl-2-butanoate. The resulting suspension was stirred for 24 hours at room temperature until a transparent solution was obtained was poured into a separating funnel The organic phase was washed with 100 ml of a saturated solution of sodium chloride The aqueous phases were extracted with diethyl ether (2×100 ml), they were washed with water (3×100 ml) and they were dried over anhydrous sodium sulphate concentrated

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 8.0 g (46 mmoles) of N-bromosuccinimide were dissolved in 60 ml of dry dichloromethane and were cooled to 0° C. To the mixture were added drop by drop 4 ml (50 mmoles) of dimethyl sulphide dissolved in 40 ml of chloromethane. The mixture was stirred for 10 minutes at 0° C. At the end of that time 5.46 (42 mmoles) of a solution of methyl 3-hydroxy-2-methylidene-butanoate in 40 ml of dichloromethane were slowly added to it. The resulting suspension was stirred for 24 hours at room temperature until a transparent solution was obtained. To this mixture was added n-hexane (100 ml) and it was poured into a separating funnel containing 200 ml of a saturated solution of sodium chloride and ice. The organic phase was washed with 100 ml of a saturated solution of sodium chloride. The aqueous phases were extracted with diethyl ether (2×100 ml), they were washed with water (3×100 ml) and they were dried over anhydrous sodium sulphate. They were vacuum concentrated giving 7.45 g (92% yield) of a syrupy liquid of methyl 2-bromomethyl-2-butanoate. The resulting suspension was stirred for 24 hours at room temperature until a transparent solution was obtained was poured into a separating funnel The organic phase was washed with 100 ml of a saturated solution of sodium chloride The aqueous phases were extracted with diethyl ether (2×100 ml), they were washed with water (3×100 ml) and they were dried over anhydrous sodium sulphate concentrated

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 8.0 g (46 mmoles) of N-bromosuccinimide were dissolved in 60 ml of dry dichloromethane and were cooled to 0° C. To the mixture were added drop by drop 4 ml (50 mmoles) of dimethyl sulphide dissolved in 40 ml of chloromethane. The mixture was stirred for 10 minutes at 0° C. At the end of that time 5.46 (42 mmoles) of a solution of methyl 3-hydroxy-2-methylidene-butanoate in 40 ml of dichloromethane were slowly added to it. The resulting suspension was stirred for 24 hours at room temperature until a transparent solution was obtained. To this mixture was added n-hexane (100 ml) and it was poured into a separating funnel containing 200 ml of a saturated solution of sodium chloride and ice. The organic phase was washed with 100 ml of a saturated solution of sodium chloride. The aqueous phases were extracted with diethyl ether (2×100 ml), they were washed with water (3×100 ml) and they were dried over anhydrous sodium sulphate. They were vacuum concentrated giving 7.45 g (92% yield) of a syrupy liquid of methyl 2-bromomethyl-2-butanoate. The resulting suspension was stirred for 24 hours at room temperature until a transparent solution was obtained was poured into a separating funnel The organic phase was washed with 100 ml of a saturated solution of sodium chloride The aqueous phases were extracted with diethyl ether (2×100 ml), they were washed with water (3×100 ml) and they were dried over anhydrous sodium sulphate concentrated

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: In a manner to that of S. E. Drews, D. Emsley, et al., in J. Chem. Soc., Perkin Transaction I, pp. 2079 and 2079 (1982), an ice cooled solution of methyl acrylate (IV) (8.6 g) in conc. HBr (16.5 ml) is mixed dropwise with acetaldehyde (V) (4.4 g) and then conc. sulfuric acid (15 ml). After stirring overnight, the reaction mixture is extracted thrice with ether. The extract is washed with saturated saline, dried over MgSO4, and concentrated. The resulting residue is distilled under reduced pressure to give methyl 2-bromomethyl-2-butenoate (III) (8.59 g). 83°~85° C./10 mmHg. the reaction mixture is extracted thrice with ether The extract is washed with saturated saline dried over MgSO4 concentrated The resulting residue is distilled under reduced pressure