4-(N-hydroxy-C-methylcarbonimidoyl)benzene-1,3-diol

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:22.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture of 1-(2,4-dihydroxy-phenyl)-ethanone oxime (4.2 g, 25 mmol) and acetonitrile/dimethylacetamide (20 mL, 3:1) cooled by a water bath (20-25° C.) was added dropwide phosphorus chloride (2.4 mL, 26.2 mmol) over a period of fifteen minutes. The mixture was stirred for an additional thirty minutes before it was poured into ice water containing sodium acetate (6 g). The mixture was stirred for ten minutes, filtered, and the filter cake was washed with water and dried in vacuo to give the title compound as a yellow solid (3.15 g): 1H NMR (CDCl3, 200 MHz): δ=7.45 (m, 1H), 6.96 (m, 1H), 6.80 (m, 1H), 2.60 (s, 3H). The mixture was stirred for ten minutes filtered the filter cake was washed with water dried in vacuo

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

Procedure: A mixture of 2,4-dihydroxyacetophenone (25 g, 0.16 mol), hydroxylamine hydrochloride (14.8 g, 0.21 mol), sodium acetate (20 g, 0.24 mol) and water/dioxane (300 mL, 1:1) was stirred at room temperature for three days before the mixture was partitioned between chloroform and water. The organic layer was dried over anhydrous sodium sulfate, concentrated in vacuo and the residue was purified by flash column chromatography on silica gel with a gradient of ethyl acetate and dichloromethane to give the title compound as a white solid (11.67 g): 1H NMR (CD3OD, 200 MHz): δ=7.26 (m, 1H), 6.28 (m, 2H), 4.88 (s, 2H), 3.29 (m, 1H), 2.24 (s, 3H). was partitioned between chloroform and water The organic layer was dried over anhydrous sodium sulfate concentrated in vacuo the residue was purified by flash column chromatography on silica gel with a gradient of ethyl acetate and dichloromethane

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:22.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture of 1-(2,4-dihydroxy-phenyl)-ethanone oxime (4.2 g, 25 mmol) and acetonitrile/dimethylacetamide (20 mL, 3:1) cooled by a water bath (20-25° C.) was added dropwide phosphorus chloride (2.4 mL, 26.2 mmol) over a period of fifteen minutes. The mixture was stirred for an additional thirty minutes before it was poured into ice water containing sodium acetate (6 g). The mixture was stirred for ten minutes, filtered, and the filter cake was washed with water and dried in vacuo to give the title compound as a yellow solid (3.15 g): 1H NMR (CDCl3, 200 MHz): δ=7.45 (m, 1H), 6.96 (m, 1H), 6.80 (m, 1H), 2.60 (s, 3H). The mixture was stirred for ten minutes filtered the filter cake was washed with water dried in vacuo

Conditions: temp:22.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture of 1-(2,4-dihydroxy-phenyl)-ethanone oxime (4.2 g, 25 mmol) and acetonitrile/dimethylacetamide (20 mL, 3:1) cooled by a water bath (20-25° C.) was added dropwide phosphorus chloride (2.4 mL, 26.2 mmol) over a period of fifteen minutes. The mixture was stirred for an additional thirty minutes before it was poured into ice water containing sodium acetate (6 g). The mixture was stirred for ten minutes, filtered, and the filter cake was washed with water and dried in vacuo to give the title compound as a yellow solid (3.15 g): 1H NMR (CDCl3, 200 MHz): δ=7.45 (m, 1H), 6.96 (m, 1H), 6.80 (m, 1H), 2.60 (s, 3H). The mixture was stirred for ten minutes filtered the filter cake was washed with water dried in vacuo

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

Procedure: A mixture of 2,4-dihydroxyacetophenone (25 g, 0.16 mol), hydroxylamine hydrochloride (14.8 g, 0.21 mol), sodium acetate (20 g, 0.24 mol) and water/dioxane (300 mL, 1:1) was stirred at room temperature for three days before the mixture was partitioned between chloroform and water. The organic layer was dried over anhydrous sodium sulfate, concentrated in vacuo and the residue was purified by flash column chromatography on silica gel with a gradient of ethyl acetate and dichloromethane to give the title compound as a white solid (11.67 g): 1H NMR (CD3OD, 200 MHz): δ=7.26 (m, 1H), 6.28 (m, 2H), 4.88 (s, 2H), 3.29 (m, 1H), 2.24 (s, 3H). was partitioned between chloroform and water The organic layer was dried over anhydrous sodium sulfate concentrated in vacuo the residue was purified by flash column chromatography on silica gel with a gradient of ethyl acetate and dichloromethane

Conditions: temp:22.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture of 1-(2,4-dihydroxy-phenyl)-ethanone oxime (4.2 g, 25 mmol) and acetonitrile/dimethylacetamide (20 mL, 3:1) cooled by a water bath (20-25° C.) was added dropwide phosphorus chloride (2.4 mL, 26.2 mmol) over a period of fifteen minutes. The mixture was stirred for an additional thirty minutes before it was poured into ice water containing sodium acetate (6 g). The mixture was stirred for ten minutes, filtered, and the filter cake was washed with water and dried in vacuo to give the title compound as a yellow solid (3.15 g): 1H NMR (CDCl3, 200 MHz): δ=7.45 (m, 1H), 6.96 (m, 1H), 6.80 (m, 1H), 2.60 (s, 3H). The mixture was stirred for ten minutes filtered the filter cake was washed with water dried in vacuo

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

Procedure: A mixture of 2,4-dihydroxyacetophenone (25 g, 0.16 mol), hydroxylamine hydrochloride (14.8 g, 0.21 mol), sodium acetate (20 g, 0.24 mol) and water/dioxane (300 mL, 1:1) was stirred at room temperature for three days before the mixture was partitioned between chloroform and water. The organic layer was dried over anhydrous sodium sulfate, concentrated in vacuo and the residue was purified by flash column chromatography on silica gel with a gradient of ethyl acetate and dichloromethane to give the title compound as a white solid (11.67 g): 1H NMR (CD3OD, 200 MHz): δ=7.26 (m, 1H), 6.28 (m, 2H), 4.88 (s, 2H), 3.29 (m, 1H), 2.24 (s, 3H). was partitioned between chloroform and water The organic layer was dried over anhydrous sodium sulfate concentrated in vacuo the residue was purified by flash column chromatography on silica gel with a gradient of ethyl acetate and dichloromethane

Conditions: temp:22.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture of 1-(2,4-dihydroxy-phenyl)-ethanone oxime (4.2 g, 25 mmol) and acetonitrile/dimethylacetamide (20 mL, 3:1) cooled by a water bath (20-25° C.) was added dropwide phosphorus chloride (2.4 mL, 26.2 mmol) over a period of fifteen minutes. The mixture was stirred for an additional thirty minutes before it was poured into ice water containing sodium acetate (6 g). The mixture was stirred for ten minutes, filtered, and the filter cake was washed with water and dried in vacuo to give the title compound as a yellow solid (3.15 g): 1H NMR (CDCl3, 200 MHz): δ=7.45 (m, 1H), 6.96 (m, 1H), 6.80 (m, 1H), 2.60 (s, 3H). The mixture was stirred for ten minutes filtered the filter cake was washed with water dried in vacuo

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

Procedure: A mixture of 2,4-dihydroxyacetophenone (25 g, 0.16 mol), hydroxylamine hydrochloride (14.8 g, 0.21 mol), sodium acetate (20 g, 0.24 mol) and water/dioxane (300 mL, 1:1) was stirred at room temperature for three days before the mixture was partitioned between chloroform and water. The organic layer was dried over anhydrous sodium sulfate, concentrated in vacuo and the residue was purified by flash column chromatography on silica gel with a gradient of ethyl acetate and dichloromethane to give the title compound as a white solid (11.67 g): 1H NMR (CD3OD, 200 MHz): δ=7.26 (m, 1H), 6.28 (m, 2H), 4.88 (s, 2H), 3.29 (m, 1H), 2.24 (s, 3H). was partitioned between chloroform and water The organic layer was dried over anhydrous sodium sulfate concentrated in vacuo the residue was purified by flash column chromatography on silica gel with a gradient of ethyl acetate and dichloromethane

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

Procedure: 1.98 g of 1-(2,4-dihydroxyphenyl)ethanone oxime (12 mM) and 1 g of potassium hydroxide (18 mM) are refluxed for 4 days in a methanol/water mixture (100 ml/100 ml). The reaction medium is subsequently concentrated under reduced pressure, acidified to pH=1 with 1N HCl, and then extracted with ethyl acetate. The organic phase obtained is dried over magnesium sulfate and concentrated under reduced pressure. The evaporation residue is purified by silica gel chromatography (methylcyclohexane/ethyl acetate gradient of 70/30 to 30/70; v/v). The expected product is obtained in the form of a white solid (0.39 g) with a yield of 22%. The reaction medium is subsequently concentrated under reduced pressure extracted with ethyl acetate The organic phase obtained is dried over magnesium sulfate concentrated under reduced pressure The evaporation residue is purified by silica gel chromatography (methylcyclohexane/ethyl acetate gradient of 70/30 to 30/70; v/v)