3-methoxybenzene-1,2-diol

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

Procedure: 3-methoxycatechol (25 g) was dissolved in benzene, mixed with dimethoxyacetal (35 ml) and a catalytic amount of tosylic acid, and then, heat-refluxed for 6 hours. The resultant was allowed to stand for cooling, alkalified by adding an aqueous sodium hydroxide solution, and extracted with ether. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over manganese sulfate, and evaporated under reduced pressure for removing the solvent. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=99/1) to give Compound IIbv-a (19.4 g, 60.5%) as a white solid. for cooling extracted with ether The organic layer was washed with a saturated aqueous sodium chloride solution dried over manganese sulfate evaporated under reduced pressure for removing the solvent The residue was purified by silica gel column chromatography (hexane/ethyl acetate=99/1) to give Compound IIbv-a (19.4 g, 60.5%) as a white solid

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

Procedure: 3-methoxycatechol (25 g) was dissolved in benzene, mixed with dimethoxyacetal (35 ml) and a catalytic amount of tosylic acid, and then, heat-refluxed for 6 hours. The resultant was allowed to stand for cooling, alkalified by adding an aqueous sodium hydroxide solution, and extracted with ether. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over manganese sulfate, and evaporated under reduced pressure for removing the solvent. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=99/1) to give Compound IIbv-a (19.4 g, 60.5%) as a white solid. for cooling extracted with ether The organic layer was washed with a saturated aqueous sodium chloride solution dried over manganese sulfate evaporated under reduced pressure for removing the solvent The residue was purified by silica gel column chromatography (hexane/ethyl acetate=99/1) to give Compound IIbv-a (19.4 g, 60.5%) as a white solid

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

Procedure: Substantially the same procedure as in Reference Example 63 was repeated using 3-methoxycatechol (18 g) and dimethoxycycloheptane (24.35 g) to give Compound IIbm-a (28.0 g, 93.5%) as a colorless solid. to give Compound IIbm-a (28.0 g, 93.5%) as a colorless solid

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

Procedure: Substantially the same procedure as in Reference Example 63 was repeated using 3-methoxycatechol (18 g) and dimethoxycycloheptane (24.35 g) to give Compound IIbm-a (28.0 g, 93.5%) as a colorless solid. to give Compound IIbm-a (28.0 g, 93.5%) as a colorless solid

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

Procedure: 3-Methoxycatechol (25 g) was dissolved in benzene, and dimethoxyacetal (35 ml) and a catalytic amount of p-toluenesulfonic acid were added thereto, followed by heating at reflux for 6 hours. After being allowed to stand for cooling, the mixture was adjusted to alkaline with an aqueous solution of sodium hydroxide, followed by extraction with ether. The organic layer was washed with a saturated saline and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=99/1) to give Compound IIbk-a (19.4 g, 60.5%) as a white solid. by heating at reflux for 6 hours for cooling followed by extraction with ether The organic layer was washed with a saturated saline dried over magnesium sulfate the solvent was distilled off under reduced pressure The residue was purified by silica gel column chromatography (hexane/ethyl acetate=99/1) to give Compound IIbk-a (19.4 g, 60.5%) as a white solid

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

Procedure: 3-Methoxycatechol (25 g) was dissolved in benzene, and dimethoxyacetal (35 ml) and a catalytic amount of p-toluenesulfonic acid were added thereto, followed by heating at reflux for 6 hours. After being allowed to stand for cooling, the mixture was adjusted to alkaline with an aqueous solution of sodium hydroxide, followed by extraction with ether. The organic layer was washed with a saturated saline and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=99/1) to give Compound IIbk-a (19.4 g, 60.5%) as a white solid. by heating at reflux for 6 hours for cooling followed by extraction with ether The organic layer was washed with a saturated saline dried over magnesium sulfate the solvent was distilled off under reduced pressure The residue was purified by silica gel column chromatography (hexane/ethyl acetate=99/1) to give Compound IIbk-a (19.4 g, 60.5%) as a white solid

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

Procedure: A mixture of 3-methoxycatechol (22.6 g), cyclopentanone (27.1 g), methyl orthoformate (34.2 g), p-toluenesulfonic acid.monohydrate (0.2 g), and benzene (300 ml) was heated under reflux for 24 hours. After being allowed to stand for cooling, a dilute solution of sodium hydroxide was added to the mixture followed by extraction with ether. The organic layer was washed with a saturated saline and dried over anhydrous potassium carbonate. The solvent was distilled off under reduced pressure to give Compound IIax-a (30 g, 90%) as a colorless oily substance. under reflux for 24 hours for cooling followed by extraction with ether The organic layer was washed with a saturated saline dried over anhydrous potassium carbonate The solvent was distilled off under reduced pressure to give Compound IIax-a (30 g, 90%) as a colorless oily substance

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

Procedure: Mixtures of 4-hydroxyindole (0.1-10%) and 5-hydroxyindole (0.1-10%), 6-hydroxyindole (0.1-10%), or 7-hydroxyindole (0.1-10%) will give a color range from black to light auburn. 5-Hydroxyindole (0.1-10%) was found to produce progressively darker browns and, eventually, black through the addition of 3-methylcatechol (0.1-10%), 3-methoxycatechol (0.1-10%), or 3,6-dimethylcatechol (0.1-10%) followed by oxidation by sodium periodate (15%). 4-Hydroxyindole (1%) was found to produce progressively lighter colors with increasing red highlights through the addition of dopamine (2-5%) when penetration of precursors was done at high pH (9.2). Therefore a range of colors from light brown to black can be obtained through combinations of 4-hydroxyindole, 5-hydroxyindole, 6-hydroxyindole, and 7-hydroxyindole with each other or various other dye precursors. Similar results were obtained in staining skin in that a range of shades from light to dark brown can be obtained through combinations of hydroxyindoles with various other dye precursors. to produce progressively darker browns to produce progressively lighter colors with increasing red highlights

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

Procedure: Mixtures of 4-hydroxyindole (0.1-10%) and 5-hydroxyindole (0.1-10%), 6-hydroxyindole (0.1-10%), or 7-hydroxyindole (0.1-10%) will give a color range from black to light auburn. 5-Hydroxyindole (0.1-10%) was found to produce progressively darker browns and, eventually, black through the addition of 3-methylcatechol (0.1-10%), 3-methoxycatechol (0.1-10%), or 3,6-dimethylcatechol (0.1-10%) followed by oxidation by sodium periodate (15%). 4-Hydroxyindole (1%) was found to produce progressively lighter colors with increasing red highlights through the addition of dopamine (2-5%) when penetration of precursors was done at high pH (9.2). Therefore a range of colors from light brown to black can be obtained through combinations of 4-hydroxyindole, 5-hydroxyindole, 6-hydroxyindole, and 7-hydroxyindole with each other or various other dye precursors. Similar results were obtained in staining skin in that a range of shades from light to dark brown can be obtained through combinations of hydroxyindoles with various other dye precursors. to produce progressively darker browns to produce progressively lighter colors with increasing red highlights

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

Procedure: A mixture of dibromoethane (10.73 g, 77 mmol) and cetyltrimethylammonium bromide (0.291 g, 0.8 mmol) in 5 cm3 of water is brought to reflux. A solution of 3-methoxycatechol (5 g, 35.7 mmol) in 20N sodium hydroxide (NaOH, 4 g in 5 cm3 of water) is added slowly. The mixture is stirred at the reflux for 12 hours and then, after cooling and extraction with ether, purification on a silica column (eluent: petroleum ether/ether, 9:1) enables 7.4 g of a colorless oil to be isolated to reflux reflux for 12 hours after cooling extraction with ether, purification on a silica column (eluent: petroleum ether/ether, 9:1) to be isolated

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

Procedure: A mixture of dibromoethane (10.73 g, 77 mmol) and cetyltrimethylammonium bromide (0.291 g, 0.8 mmol) in 5 cm3 of water is brought to reflux. A solution of 3-methoxycatechol (5 g, 35.7 mmol) in 20N sodium hydroxide (NaOH, 4 g in 5 cm3 of water) is added slowly. The mixture is stirred at the reflux for 12 hours and then, after cooling and extraction with ether, purification on a silica column (eluent: petroleum ether/ether, 9:1) enables 7.4 g of a colorless oil to be isolated to reflux reflux for 12 hours after cooling extraction with ether, purification on a silica column (eluent: petroleum ether/ether, 9:1) to be isolated

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

Procedure: A mixture of 3-methoxy-benzene-1,2-diol (1.161 g, 8.28 mmol) in DMF (10 mL) was added to bromo-chloro-methane (611 ul, 1.1 equivalents) and stirred at 90 degrees Celsius for 4 hours. The mixture was poured into water and extracted with dichloromethane. The organic layer was poured thru a phase separator cartridge and concentrated to dryness. The crude product is a yellow liquid. The liquid was purified by column chromatography yielding 1.21 g, (96%). 1H-NMR (DMSO, 500 MHz) 6.7 (t, 1H), 6.63 (d, 1H), 6.58 (d, 1H), 5.97 (s, 2H), 3.83 (s, 3H) HPLC (method A) 2.86 min. extracted with dichloromethane The organic layer was poured thru a phase separator cartridge concentrated to dryness The liquid was purified by column chromatography yielding 1.21 g, (96%) 1H-NMR (DMSO, 500 MHz) 6.7 (t, 1H), 6.63 (d, 1H), 6.58 (d, 1H), 5.97 (s, 2H), 3.83 (s, 3H) HPLC (method A) 2.86 min.