4-amino-2,6-dimethylbenzaldehyde

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

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

実験手順: 4-Amino-2,6-dimethylbenzaldehyde (3.0 g, 20.1 mmol) was taken up in enough 42% HBF4 until the suspension stirred well and then was cooled to 0° C. To this was added a solution of NaNO2 (1.39 g, 20.1 mmol) in water (10 mL) slowly. After 30 min at 0° C., MeOH (50 mL) was added followed by Pd(OAc)2 (677 mg) and diethyl allylphosphonate (5.38 g, 30.2 mmol). The reaction mixture was heated to 80° C. for 30 min and the suspension was filtered through Celite, washed with CH2Cl2, and the filtrate was extracted with CH2Cl2. The combined organic layers were washed with water, brine, dried with MgSO4, and filtered. The solvent was removed under reduced pressure and the residue was purified by flash chromatography using a gradient of heptane/EtOAc (10:1 to 5:1 then followed by 100% EtOAc) to give [(E)-3-(4-formyl-3,5-dimethylphenyl)-allyl]-phosphonic acid diethyl ester as a light yellow oil. The reaction mixture was heated to 80° C. for 30 min the suspension was filtered through Celite washed with CH2Cl2 the filtrate was extracted with CH2Cl2 The combined organic layers were washed with water, brine dried with MgSO4 filtered The solvent was removed under reduced pressure the residue was purified by flash chromatography

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

実験手順: 4-Amino-2,6-dimethylbenzaldehyde (149 mg, 1.0 mmol)) was taken up in enough 42% HBF4 until the suspension stirred well and then was cooled to 0° C. To this was added a solution of NaNO2 (69 mg, 1.0 mmol) in water (0.5 mL) slowly. After 30 minutes at 0° C., MeOH (3 mL) was added and followed by Pd(OAc)2 (7.5 mg) and vinylphosphonic acid diethyl ester (197 mg, 1.2 mmol). The reaction mixture was heated at 80° C. for 30 min and the suspension was filtered through Celite, washed with CH2Cl2, and the filtrate was extracted with CH2Cl2. The organic layer was washed with water, brine, dried with MgSO4, and filtered. The solvent was removed under reduced pressure and the residue was purified by flash chromatography using heptane/EtOAc (4:1 then followed by 100% EtOAc) to give [(E)-2-(4-formyl-3,5-dimethylphenyl)-vinyl]-phosphonic acid diethyl ester as a colorless oil. The reaction mixture was heated at 80° C. for 30 min the suspension was filtered through Celite washed with CH2Cl2 the filtrate was extracted with CH2Cl2 The organic layer was washed with water, brine dried with MgSO4 filtered The solvent was removed under reduced pressure the residue was purified by flash chromatography

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

実験手順: The above 4-amino-2,6-dimethylbenzaldehyde (1.0 g, 6.71 mmol) was taken up in enough 42% HBF4 until the suspension stirred well and then was cooled to 0° C. A solution of NaNO2 (463 mg, 6.71 mmol) in water (5 mL) was added slowly and after 30 min at 0° C., MeOH (20 mL) was added followed by Pd(OAc)2 (229 mg) and methyl acrylate (1.16 g, 13.42 mmol). The reaction mixture was heated at 80° C. for 30 min then the suspension was filtered through Celite and washed with CH2Cl2. The combined organic layers were washed with water, brine, dried with MgSO4, and filtered. The solvent was removed under reduced pressure and the residue was purified by flash chromatography using a 10/1 to 5/1 gradient of heptane/EtOAc to give 3-(4-formyl-3,5-dimethylphenyl)-acrylic acid methyl ester as a light yellow solid. The reaction mixture was heated at 80° C. for 30 min the suspension was filtered through Celite washed with CH2Cl2 The combined organic layers were washed with water, brine dried with MgSO4 filtered The solvent was removed under reduced pressure the residue was purified by flash chromatography