methyl 5-amino-2-chlorobenzoate

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

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

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

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

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

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

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

Procedure: To a mixture of 3-[2-methoxy-4-(5-phenylpentyloxy)phenyl]propanoic acid (342 mg), 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide hydrochloride (288 mg), 1-hydroxybenzotriazole-1-hydrate (153 mg) and dimethylformamide (5 mL) was added methyl 2-chloro-5-aminobenzoate (265 mg) and triethylamine (0.7 mL). To the reaction mixture was added dimethylaminopyridine (50 mg). The reaction mixture was stirred at room temperature overnight. 1N hydrochloric acid was added to the reaction mixture, which was extracted with ethyl acetate. The extract was washed with saturated aqueous solution of sodium hydrogen carbonate and brine, dried over an anhydrous sodium sulfate and concentrated. The obtained residue was purified by column chromatography on silica gel (hexane:ethyl acetate=4:1) to give the title compound (300 mg) having the following physical data. was extracted with ethyl acetate The extract was washed with saturated aqueous solution of sodium hydrogen carbonate and brine dried over an anhydrous sodium sulfate concentrated The obtained residue was purified by column chromatography on silica gel (hexane:ethyl acetate=4:1)

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

Procedure: Thionyl chloride (4.1 g, 0.034 mole) was added to a stirred mixture of 5,6-dihydro-2-methyl-1,4-oxathiin-3-carboxylic acid (4.3 g, 0.027 mole) and methylene chloride (35 ml). The mixture was warmed to a gentle reflux for about 3.5 hours, left stirring overnight at room temperature, and then evaporated under reduced pressure. The solid residue, crude 5,6-dihydro-2-methyl-1,4-oxathiin-3-carbonyl chloride, was dissolved in methylene chloride (50 ml) and the solution treated dropwise at 5°-10° C. over 2 hours with a solution of methyl 5-amino-2-chlorobenzoate (5.1 g, 0.027 mole) and triethylamine (3.1 g, 0.031 mole) in methylene chloride (35 ml). The reaction mixture was stirred at room temperature for a further 3 hours and worked up by washing in sequence with water (50 ml), dilute hydrochloric acid (3.5%, 50 ml), water (50 ml), dilute sodium hydroxide (2%, 25 ml) and water (50 ml). The methylene chloride was then evaporated to leave an oil (8.2 g), which slowly solidified. Recrystallization from methanol (75 ml) gave a beige solid, m.p. 115°-117° C. (5.5 g, 62.5% yield). The mixture was warmed to a gentle reflux for about 3.5 hours left evaporated under reduced pressure The solid residue, crude 5,6-dihydro-2-methyl-1,4-oxathiin-3-carbonyl chloride, was dissolved in methylene chloride (50 ml) The reaction mixture was stirred at room temperature for a further 3 hours by washing in sequence with water (50 ml), dilute hydrochloric acid (3.5%, 50 ml), water (50 ml), dilute sodium hydroxide (2%, 25 ml) and water (50 ml) The methylene chloride was then evaporated

Conditions: temp:2.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Compound (78) (9 g, 48.5 mmol) was subjected to diazotization using NaNO2 (4.5 g 48.5 mmol) in water (50 mL) and H2SO4 (10%, 100 mL). Excess nitrous acid was neutralized with urea. The reaction mixture was poured into a suspension of CuSO4. 5H2O (144 g, 577 mmol) and Cu2O (5.22 g, 41.4 mmol) in water (900 mL) at 0° C. The reaction mixture was stirred for 15 min. at 0-5° C. and was then extracted using diethyl ether (200 mL×3). The organic extract was washed, dried (anhy. Na2SO4), concentrated and purified using a silica gel column and 10% EtOAc in petroleum ether (60-80° C.) as eluant to obtain the title compound(80). at 0° C was then extracted The organic extract was washed dried (anhy Na2SO4), concentrated purified a silica gel column and 10% EtOAc in petroleum ether (60-80° C.) to obtain the title compound(80)

Conditions: temp:86.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-Chloro-5-aminobenzoic acid (1.5 g, 8.74 mmol) was dissolved in methanol (8 ml) and sulphuric acid (1 ml) was added drop wise with stirring. The reaction mixture was then heated to 86° C. for 18 hr then allowed to cool to room temperature before solvent was removed in vacuo. The resultant purple solid was then dissolved in water and 5M NaOH solution was added until pH 7 was reached. This was then washed with ethyl acetate. The organics were dried over Na2SO4 and solvent was removed in vacuo to give the title compound as a purple oil (1.51 g, 8.12 mmol, 93%): LCMS: [M+H]+=186, Rt=0.88 min, 95% purity. to cool to room temperature before solvent was removed in vacuo The resultant purple solid was then dissolved in water 5M NaOH solution was added until pH 7 This was then washed with ethyl acetate The organics were dried over Na2SO4 and solvent was removed in vacuo

Conditions: temp:86.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-Chloro-5-aminobenzoic acid (1.5 g, 8.74 mmol) was dissolved in methanol (8 ml) and sulphuric acid (1 ml) was added drop wise with stirring. The reaction mixture was then heated to 86° C. for 18 hr then allowed to cool to room temperature before solvent was removed in vacuo. The resultant purple solid was then dissolved in water and 5M NaOH solution was added until pH 7 was reached. This was then washed with ethyl acetate. The organics were dried over Na2SO4 and solvent was removed in vacuo to give the title compound as a purple oil (1.51 g, 8.12 mmol, 93%): LCMS: [M+H]+=186, Rt=0.88 min, 95% purity. to cool to room temperature before solvent was removed in vacuo The resultant purple solid was then dissolved in water 5M NaOH solution was added until pH 7 This was then washed with ethyl acetate The organics were dried over Na2SO4 and solvent was removed in vacuo

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

Procedure: 5-Amino-2-chloro-benzoic acid methyl ester (3.5 g, 21.2 mmol) was dissolved in glacial acetic acid (80 ml) and 5.5 ml of concentrated HCl was added. After stirring with an overhead stirrer for 30 minutes at ambient temperature the mixture was cooled to 10° C. and a solution of NaNO2 (1.6 g) in water (4 ml) was added dropwise, keeping the internal temperature below 15° C. During this addition the reaction mixture changed from amber to a cloudy orange. After 30 minutes sodium acetate (3.8 g, 46.6 mmol) and (3-ethoxycarbonylamino-3-oxo-propionyl)-carbamic acid ethyl ester (5.7 g, 23.3 mmol) were added at once. After 10 minutes the reaction was warmed to ambient temperature. After 1 hour additional sodium acetate (1.7 g, 21.2 mmol) was added and the reaction mixture was heated at reflux. After 3 hours the deep red-brown mixture was treated with 50% sulfuric acid (23 ml) and heated again at reflux. After 2 hours the mixture was concentrated under reduced pressure and then water (200 ml) was added. After stirring for 30 minutes the gold precipitate (3.5 g) was collected by filtration. The resulting solid was suspended in 3 ml of mercaptoacetic acid and stirred at 175° C. After 4 hours the mixture was allowed to cool and sit for 16 hours. The mixture was diluted with water (100 ml) and stirred for 1 hour. The resulting brown solid (2.1 g) was collected by filtration. Mass spectrum [M-1] 246.4. was cooled to 10° C. the internal temperature below 15° C During this addition the reaction mixture After 10 minutes the reaction was warmed to ambient temperature the reaction mixture was heated at reflux heated again at reflux After 2 hours the mixture was concentrated under reduced pressure water (200 ml) was added After stirring for 30 minutes the gold precipitate (3.5 g) was collected by filtration stirred at 175° C After 4 hours the mixture was allowed to cool sit for 16 hours The mixture was diluted with water (100 ml) stirred for 1 hour The resulting brown solid (2.1 g) was collected by filtration