二甲基 4,5-二氯苯-1,2-二甲酸二甲酯

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of dimethyl 4,5-dichlorophthalate A5 (98.86 g, 375.78 mmol) in tetrahydrofuran (150 mL) is added dropwise over 1 h to a mechanically stirred suspension of LAH (20.8 g, 548.1 mmol) in tetrahydrofuran (1.5 L). During the addition, the reaction is cooled in an ice-water bath. When the addition is completed, the reaction is stirred overnight at RT. The excess LAH is decomposed by cautious addition of water (20 mL), 10% aqueous NaOH (40 mL) and water (20 mL). The solids are removed by filtration through a celite pad and washed with tetrahydrofuran. The combined filtrate and wash is concentrated in vacuo on a rotary evaporator to afford crude 251 as white solid that is purified by crystallization from acetone (150 mL)-heptane (150 mL). The crystals are collected by filtration, washed with heptane and dried to give 4,5-dichloro-1,2-bis(hydroxymethyl)benzene (37.2 g). The combined filtrate and wash afforded a second crop of 251 (18.8 g, 24.1%). [L. A. Levy, Synth. Commun., 13, 639-648 (1983); O. Farooq, Synthesis, 1035-1036 (1994)] During the addition the reaction is cooled in an ice-water bath When the addition The solids are removed by filtration through a celite pad washed with tetrahydrofuran The combined filtrate and wash is concentrated in vacuo on a rotary evaporator

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of dimethyl 4,5-dichlorophthalate A5 (98.86 g, 375.78 mmol) in tetrahydrofuran (150 mL) is added dropwise over 1 h to a mechanically stirred suspension of LAH (20.8 g, 548.1 mmol) in tetrahydrofuran (1.5 L). During the addition, the reaction is cooled in an ice-water bath. When the addition is completed, the reaction is stirred overnight at RT. The excess LAH is decomposed by cautious addition of water (20 mL), 10% aqueous NaOH (40 mL) and water (20 mL). The solids are removed by filtration through a celite pad and washed with tetrahydrofuran. The combined filtrate and wash is concentrated in vacuo on a rotary evaporator to afford crude 251 as white solid that is purified by crystallization from acetone (150 mL)-heptane (150 mL). The crystals are collected by filtration, washed with heptane and dried to give 4,5-dichloro-1,2-bis(hydroxymethyl)benzene (37.2 g). The combined filtrate and wash afforded a second crop of 251 (18.8 g, 24.1%). [L. A. Levy, Synth. Commun., 13, 639-648 (1983); O. Farooq, Synthesis, 1035-1036 (1994)] During the addition the reaction is cooled in an ice-water bath When the addition The solids are removed by filtration through a celite pad washed with tetrahydrofuran The combined filtrate and wash is concentrated in vacuo on a rotary evaporator