3,4-dihydroxy-5-methoxybenzaldehyde

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a vial was placed 0.5 g (3.0 mmol) of 3,4-dihydroxy-5-methoxybenzaldehyde, 414 mg (3.0 mmol) of K2CO3, and 3 mL of anhydrous DMF. To this mixture was added, 0.56 g (3.0 mmol) of 1,2-dibromoethane dropwise. The vial was sealed and heated to 100° C. overnight. Water was added to the reaction and the mixture was extracted with diethyl ether. The organic extract was washed with brine, dried (Na2SO4), filtered, and concentrated to give the crude product. The material was purified by silica gel chromatography using 50% ethyl acetate/hexane as the eluent to afford 0.25 g (43%) of the pure aldehyde 10. To this mixture was added The vial was sealed the mixture was extracted with diethyl ether The organic extract was washed with brine dried (Na2SO4) filtered concentrated to give the crude product The material was purified by silica gel chromatography

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: U.S. Pat. No. 3,855,306 discloses methylation of 5-hydroxyvanillin (initially prepared from vanillin by bromination and subsequent hydrolysis) with dimethyl sulfate in the presence of an alkali carbonate in an organic medium such as acetone. 3,4,5,-Trimethoxybenzaldehyde in yields of about 94% are obtained in this method, but the reaction is slow and operating with organic solvents presents disadvantages of operation and cost.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: After adding 1.5 g of potassium carbonate and 1.2 g of 1,3-dibromopropane to a solution of 920 mg of 3,4-dihydroxy-5-methoxybenzaldehyde [CAS No. 859785-71-0] in 10 ml of DMF, the mixture was stirred at 60° C. for 3 hours. Water was added to the reaction mixture, and extraction was performed with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate. The desiccating agent was filtered off and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate-heptane) to give the title compound (604 mg) as an oil. The organic layer was dried over anhydrous magnesium sulfate The desiccating agent was filtered off the filtrate was concentrated under reduced pressure The residue was purified by silica gel column chromatography (ethyl acetate-heptane)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: After adding 1.5 g of potassium carbonate and 1.2 g of 1,3-dibromopropane to a solution of 920 mg of 3,4-dihydroxy-5-methoxybenzaldehyde [CAS No. 859785-71-0] in 10 ml of DMF, the mixture was stirred at 60° C. for 3 hours. Water was added to the reaction mixture, and extraction was performed with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate. The desiccating agent was filtered off and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate-heptane) to give the title compound (604 mg) as an oil. The organic layer was dried over anhydrous magnesium sulfate The desiccating agent was filtered off the filtrate was concentrated under reduced pressure The residue was purified by silica gel column chromatography (ethyl acetate-heptane)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: After adding 1.5 g of potassium carbonate and 1.2 g of 1,3-dibromopropane to a solution of 920 mg of 3,4-dihydroxy-5-methoxybenzaldehyde [CAS No. 859785-71-0] in 10 ml of DMF, the mixture was stirred at 60° C. for 3 hours. Water was added to the reaction mixture, and extraction was performed with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate. The desiccating agent was filtered off and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate-heptane) to give the title compound (604 mg) as an oil. The organic layer was dried over anhydrous magnesium sulfate The desiccating agent was filtered off the filtrate was concentrated under reduced pressure The residue was purified by silica gel column chromatography (ethyl acetate-heptane)

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a vial was placed 0.5 g (3.0 mmol) of 3,4-dihydroxy-5-methoxybenzaldehyde, 414 mg (3.0 mmol) of K2CO3, and 3 mL of anhydrous DMF. To this mixture was added, 0.56 g (3.0 mmol) of 1,2-dibromoethane dropwise. The vial was sealed and heated to 100° C. overnight. Water was added to the reaction and the mixture was extracted with diethyl ether. The organic extract was washed with brine, dried (Na2SO4), filtered, and concentrated to give the crude product. The material was purified by silica gel chromatography using 50% ethyl acetate/hexane as the eluent to afford 0.25 g (43%) of the pure aldehyde 10. To this mixture was added The vial was sealed the mixture was extracted with diethyl ether The organic extract was washed with brine dried (Na2SO4) filtered concentrated to give the crude product The material was purified by silica gel chromatography

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: U.S. Pat. No. 3,855,306 discloses methylation of 5-hydroxyvanillin (initially prepared from vanillin by bromination and subsequent hydrolysis) with dimethyl sulfate in the presence of an alkali carbonate in an organic medium such as acetone. 3,4,5,-Trimethoxybenzaldehyde in yields of about 94% are obtained in this method, but the reaction is slow and operating with organic solvents presents disadvantages of operation and cost.