2-乙酰基-4-戊酮酸乙酯

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

实验步骤: To a stirred and refluxing solution of ethyl sodioacetoacetate (0.5 mole, 78g.) and sodium iodide (1g.) in dry acetone (250 ml.) was added chloroactone (0.54 mol. 50g.) over a period of ten minutes. After one hour the acetone was distilled from the reaction mixture and the residue was diluted with 400 ml. water. The preciptated oil was extracted with ether and the ether removed to yield the intermediate 3-carbethoxy-2,5-hexanedione (75g.). The intermediate (26.4g.) was cyclized by heating under reflux over 5 g. anhydrous oxalic acid for 11/4 hours. The crude ester was saponified by heating under reflux for 45 minutes with potassium hydroxide (26g.) in methanol (200 ml.). The methanol was removed, the residue dissolved in water and the solution acidified to yield 2,5-dimethyl-3-furoic acid (18g.), m.p. 130°-133°. by heating under reflux over 5 g 4 hours by heating The methanol was removed the residue dissolved in water

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

实验步骤: To a stirred and refluxing solution of ethyl sodioacetoacetate (0.5 mole, 78g.) and sodium iodide (1g.) in dry acetone (250 ml.) was added chloroactone (0.54 mol. 50g.) over a period of ten minutes. After one hour the acetone was distilled from the reaction mixture and the residue was diluted with 400 ml. water. The preciptated oil was extracted with ether and the ether removed to yield the intermediate 3-carbethoxy-2,5-hexanedione (75g.). The intermediate (26.4g.) was cyclized by heating under reflux over 5 g. anhydrous oxalic acid for 11/4 hours. The crude ester was saponified by heating under reflux for 45 minutes with potassium hydroxide (26g.) in methanol (200 ml.). The methanol was removed, the residue dissolved in water and the solution acidified to yield 2,5-dimethyl-3-furoic acid (18g.), m.p. 130°-133°. After one hour the acetone was distilled from the reaction mixture the residue was diluted with 400 ml The preciptated oil was extracted with ether the ether removed

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

实验步骤: Utilizing the procedure outlined in Example 85, ethyl 2-acetyl-4-oxopentanoate (6.37 g, 34.2 mmol) was dissolved in 20 mL of EtOH. 2,6-dibromo-4-aminophenol (11.6g, 34.2mmol) were reacted to afford ethyl 1-(3,5-dibromo-4-hydroxyphenyl)-2,5-dimethyl-1H-pyrrole-3-carboxylate was taken on without further purification. MS (ESI) 418 (M+H)+.

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

实验步骤: Utilizing the procedure outlined in Example 85, ethyl 2-acetyl-4-oxopentanoate (6.37 g, 34.2 mmol) was dissolved in 20 mL of EtOH. 2,6-dibromo-4-aminophenol (11.6g, 34.2mmol) were reacted to afford ethyl 1-(3,5-dibromo-4-hydroxyphenyl)-2,5-dimethyl-1H-pyrrole-3-carboxylate was taken on without further purification. MS (ESI) 418 (M+H)+.

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

实验步骤: To a stirred and refluxing solution of ethyl sodioacetoacetate (0.5 mole, 78g.) and sodium iodide (1g.) in dry acetone (250 ml.) was added chloroactone (0.54 mol. 50g.) over a period of ten minutes. After one hour the acetone was distilled from the reaction mixture and the residue was diluted with 400 ml. water. The preciptated oil was extracted with ether and the ether removed to yield the intermediate 3-carbethoxy-2,5-hexanedione (75g.). The intermediate (26.4g.) was cyclized by heating under reflux over 5 g. anhydrous oxalic acid for 11/4 hours. The crude ester was saponified by heating under reflux for 45 minutes with potassium hydroxide (26g.) in methanol (200 ml.). The methanol was removed, the residue dissolved in water and the solution acidified to yield 2,5-dimethyl-3-furoic acid (18g.), m.p. 130°-133°. by heating under reflux over 5 g 4 hours by heating The methanol was removed the residue dissolved in water

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

实验步骤: To a stirred and refluxing solution of ethyl sodioacetoacetate (0.5 mole, 78g.) and sodium iodide (1g.) in dry acetone (250 ml.) was added chloroactone (0.54 mol. 50g.) over a period of ten minutes. After one hour the acetone was distilled from the reaction mixture and the residue was diluted with 400 ml. water. The preciptated oil was extracted with ether and the ether removed to yield the intermediate 3-carbethoxy-2,5-hexanedione (75g.). The intermediate (26.4g.) was cyclized by heating under reflux over 5 g. anhydrous oxalic acid for 11/4 hours. The crude ester was saponified by heating under reflux for 45 minutes with potassium hydroxide (26g.) in methanol (200 ml.). The methanol was removed, the residue dissolved in water and the solution acidified to yield 2,5-dimethyl-3-furoic acid (18g.), m.p. 130°-133°. After one hour the acetone was distilled from the reaction mixture the residue was diluted with 400 ml The preciptated oil was extracted with ether the ether removed