4-(dibutylamino)-2-hydroxybenzaldehyde

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

Procedure: Firstly, the starting compound N,N-dibutyl-4-amino-2-hydroxy-benzaldehyde had to be prepared by Vilsmeyer formylation of N,N-dibutyl-3-amino-phenol. The Vilsmeyer reagent was prepared by slow addition of 4.7 ml (0.0497 mol) of phosphorus oxychloride to 15 ml (0.189 mol) of N,N-dimethyl formamide with stirring for 15 minutes at room temperature. Stirring was continued for 30 more minutes before this Vilsmeyer reagent was used. 11 g (0.497 mol) N,N-dibutyl-3-amino-phenol, prepared by alkylation of 3-aminophenol after the procedure described in EP 0356173 was dissolved in 13 ml N,N-dimethyl formamide. This solution was added dropwise at room temperature to the Vilsmeyer reagent described above. The solution was stirred for 3 h, heated to 50° C. for 10 minutes. The solution was cooled to room temperature and stirred for another 2 h. Then, the reaction mixture was poured onto 70 g ice and stirred for 1 h. The aequous layer was extracted three times with 100 ml chloroform. The combined organic layers were evaporated in vacuo. The raw product was purified by column chromatography (450 g silicagel, eluent hexane/ethyl acetate 15:1, vol. ratio). 3.2 g (26%) N,N-Dibutylamino-2-hydroxy-benzaldehyde was obtained as an orange oily compound. Stirring This solution was added dropwise at room temperature to the Vilsmeyer reagent The solution was stirred for 3 h heated to 50° C. for 10 minutes The solution was cooled to room temperature stirred for another 2 h stirred for 1 h The aequous layer was extracted three times with 100 ml chloroform The combined organic layers were evaporated in vacuo The raw product was purified by column chromatography (450 g silicagel, eluent hexane/ethyl acetate 15:1, vol. ratio)

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

Procedure: Firstly, the starting compound N,N-dibutyl-4-amino-2-hydroxy-benzaldehyde had to be prepared by Vilsmeyer formylation of N,N-dibutyl-3-amino-phenol. The Vilsmeyer reagent was prepared by slow addition of 4.7 ml (0.0497 mol) of phosphorus oxychloride to 15 ml (0.189 mol) of N,N-dimethyl formamide with stirring for 15 minutes at room temperature. Stirring was continued for 30 more minutes before this Vilsmeyer reagent was used. 11 g (0.497 mol) N,N-dibutyl-3-amino-phenol, prepared by alkylation of 3-aminophenol after the procedure described in EP 0356173 was dissolved in 13 ml N,N-dimethyl formamide. This solution was added dropwise at room temperature to the Vilsmeyer reagent described above. The solution was stirred for 3 h, heated to 50° C. for 10 minutes. The solution was cooled to room temperature and stirred for another 2 h. Then, the reaction mixture was poured onto 70 g ice and stirred for 1 h. The aequous layer was extracted three times with 100 ml chloroform. The combined organic layers were evaporated in vacuo. The raw product was purified by column chromatography (450 g silicagel, eluent hexane/ethyl acetate 15:1, vol. ratio). 3.2 g (26%) N,N-Dibutylamino-2-hydroxy-benzaldehyde was obtained as an orange oily compound. Stirring This solution was added dropwise at room temperature to the Vilsmeyer reagent The solution was stirred for 3 h heated to 50° C. for 10 minutes The solution was cooled to room temperature stirred for another 2 h stirred for 1 h The aequous layer was extracted three times with 100 ml chloroform The combined organic layers were evaporated in vacuo The raw product was purified by column chromatography (450 g silicagel, eluent hexane/ethyl acetate 15:1, vol. ratio)

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

Procedure: Firstly, the starting compound N,N-dibutyl-4-amino-2-hydroxy-benzaldehyde had to be prepared by Vilsmeyer formylation of N,N-dibutyl-3-amino-phenol. The Vilsmeyer reagent was prepared by slow addition of 4.7 ml (0.0497 mol) of phosphorus oxychloride to 15 ml (0.189 mol) of N,N-dimethyl formamide with stirring for 15 minutes at room temperature. Stirring was continued for 30 more minutes before this Vilsmeyer reagent was used. 11 g (0.497 mol) N,N-dibutyl-3-amino-phenol, prepared by alkylation of 3-aminophenol after the procedure described in EP 0356173 was dissolved in 13 ml N,N-dimethyl formamide. This solution was added dropwise at room temperature to the Vilsmeyer reagent described above. The solution was stirred for 3 h, heated to 50° C. for 10 minutes. The solution was cooled to room temperature and stirred for another 2 h. Then, the reaction mixture was poured onto 70 g ice and stirred for 1 h. The aequous layer was extracted three times with 100 ml chloroform. The combined organic layers were evaporated in vacuo. The raw product was purified by column chromatography (450 g silicagel, eluent hexane/ethyl acetate 15:1, vol. ratio). 3.2 g (26%) N,N-Dibutylamino-2-hydroxy-benzaldehyde was obtained as an orange oily compound. Stirring This solution was added dropwise at room temperature to the Vilsmeyer reagent The solution was stirred for 3 h heated to 50° C. for 10 minutes The solution was cooled to room temperature stirred for another 2 h stirred for 1 h The aequous layer was extracted three times with 100 ml chloroform The combined organic layers were evaporated in vacuo The raw product was purified by column chromatography (450 g silicagel, eluent hexane/ethyl acetate 15:1, vol. ratio)

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

Procedure: In 40 ml of N,N-dimethylformamide were dissolved 5.39 g (21.6 mmol) of 4-dibutylamino-2-hydroxybenzaldehyde and 4.08 g (60.0 mmol) of imidazole. Next, 6.13 g (22.3 mmol) of tert-butylchlorodiphenylsilane was added dropwise thereto with stirring at room temperature. The mixture was stirred for 3.5 hours. After the reaction mixture was poured into water, extraction with ethyl acetate, washing with a saturated saline solution, drying over anhydrous sodium sulfate, and concentration were performed. The residue was purified by silica gel column chromatography to give 10.3 g of a colorless oily matter (yield: 97.7%). The mixture was stirred for 3.5 hours washing with a saturated saline solution drying over anhydrous sodium sulfate, and concentration The residue was purified by silica gel column chromatography to give 10.3 g of a colorless oily matter (yield: 97.7%)

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In 20 ml of 1-methyl-2-pyrrolidone were dissolved 1.86 g (7.46 mmol) of 4-dibutylamino-2-hydroxybenzaldehyde and 1.66 g (9.71 mmol) of benzyl bromide. To this mixture was added 2.06 g (14.9 mmol) of anhydrous potassium carbonate and the mixture was stirred with heating at 50° C. for 2 hours. After the reaction mixture was added to water, extraction with ethyl acetate, washing with a saturated saline solution, drying over anhydrous sodium sulfate, and concentration were performed. The residue was purified by silica gel column chromatography to give 2.31 g of a pale yellow crystal (yield: 91.3%). washing with a saturated saline solution drying over anhydrous sodium sulfate, and concentration The residue was purified by silica gel column chromatography

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In 20 ml of 1-methyl-2-pyrrolidone were dissolved 2.49 g (9.9 mmol) of 4-dibutylamino-2-hydroxybenzaldehyde and 3.5 g (24.6 mmol) of methyl iodide. To this mixture was added 4.1 g (29.7 mmol) of anhydrous potassium carbonate and the mixture was stirred with heating at 50° C. for 2 hours. After the reaction mixture was added to water, extraction with ethyl acetate, washing with a saturated saline solution, drying over anhydrous sodium sulfate, and concentration were performed. The residue was purified by silica gel column chromatography to give 2.58 g of a colorless oily matter (yield: 98.1%). washing with a saturated saline solution drying over anhydrous sodium sulfate, and concentration The residue was purified by silica gel column chromatography to give 2.58 g of a colorless oily matter (yield: 98.1%)

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

Procedure: Firstly, the starting compound N,N-dibutyl-4-amino-2-hydroxy-benzaldehyde had to be prepared by Vilsmeyer formylation of N,N-dibutyl-3-amino-phenol. The Vilsmeyer reagent was prepared by slow addition of 4.7 ml (0.0497 mol) of phosphorus oxychloride to 15 ml (0.189 mol) of N,N-dimethyl formamide with stirring for 15 minutes at room temperature. Stirring was continued for 30 more minutes before this Vilsmeyer reagent was used. 11 g (0.497 mol) N,N-dibutyl-3-amino-phenol, prepared by alkylation of 3-aminophenol after the procedure described in EP 0356173 was dissolved in 13 ml N,N-dimethyl formamide. This solution was added dropwise at room temperature to the Vilsmeyer reagent described above. The solution was stirred for 3 h, heated to 50° C. for 10 minutes. The solution was cooled to room temperature and stirred for another 2 h. Then, the reaction mixture was poured onto 70 g ice and stirred for 1 h. The aequous layer was extracted three times with 100 ml chloroform. The combined organic layers were evaporated in vacuo. The raw product was purified by column chromatography (450 g silicagel, eluent hexane/ethyl acetate 15:1, vol. ratio). 3.2 g (26%) N,N-Dibutylamino-2-hydroxy-benzaldehyde was obtained as an orange oily compound. Stirring This solution was added dropwise at room temperature to the Vilsmeyer reagent The solution was stirred for 3 h heated to 50° C. for 10 minutes The solution was cooled to room temperature stirred for another 2 h stirred for 1 h The aequous layer was extracted three times with 100 ml chloroform The combined organic layers were evaporated in vacuo The raw product was purified by column chromatography (450 g silicagel, eluent hexane/ethyl acetate 15:1, vol. ratio)