1-(3-amino-2-hydroxyphenyl)ethanone

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

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

Procedure: A solution of crude 1-benzyl-1H-tetrazole-5-carbonyl chloride (prepared from 2.4 g of potassium 1-benzyl-1H-tetrazole-5-carboxylate in the manner hereinbefore described in Reference Example 3) in dry methylene chloride (50 ml) was added to a stirred solution of 3-amino-2-hydroxyacetophenone (1.5 g) and pyridine (0.9 g) in dry methylene chloride (40 ml) at 10° C. After standing at room temperature overnight, the solution was evaporated in vacuo and the resulting solid residue was recrystallised from a large volume of ethanol to give 3'-acetyl-1-benzyl-2'-hydroxy-1H-tetrazole-5-carboxanilide (1.5 g), in the form of pale yellow needles, m.p. 155°-157° C. the solution was evaporated in vacuo the resulting solid residue was recrystallised from a large volume of ethanol

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

Procedure: A solution of 2-hydroxy-3-nitroacetophenone [4.0 g; prepared by the method of Allen et al., J. Chem. Soc., (1949), 821] in ethanol (150 ml) was hydrogenated at 25° C. and 50 p.s.i. for 2.5 hours, using a catalyst of platinum on charcoal. The mixture was filtered and the filtrate was evaporated in vacuo to give a black solid, which was purified by chromatography on a column of silica gel, using diethyl ether as eluant. The fastest moving band (yellow) was collected to give 3-amino-2-hydroxyacetophenone (3.0 g), in the form of a bright yellow solid, m.p. 95°-97° C. prepared by the method of Allen et al., J was hydrogenated at 25° C. The mixture was filtered the filtrate was evaporated in vacuo to give a black solid, which was purified by chromatography on a column of silica gel was collected

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

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

Procedure: Potassium O-ethyl dithiocarbonate (241 mg, 1.5 mmol) was added to a solution of 3-amino-2-hydroxyacetophenone (113 mg, 0.75 mmol) in ethanol (10 ml) and the mixture was heated to reflux for 16 hours. The reaction was concentrated, water (20 ml) was added thereto and the mixture was adjusted to pH, 3-4 with diluted hydrochloric acid. The separated matter was collected by filtration and dried by heating in vacuo to provide 134 mg (yield 92%) of 7-acetyl-2-mercaptobenzooxazole as a dark solid. the mixture was heated to reflux for 16 hours The reaction was concentrated water (20 ml) was added The separated matter was collected by filtration dried by heating in vacuo

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

Procedure: Potassium O-ethyl dithiocarbonate (241 mg, 1.5 mmol) was added to a solution of 3-amino-2-hydroxyacetophenone (113 mg, 0.75 mmol) in ethanol (10 ml) and the mixture was heated to reflux for 16 hours. The reaction was concentrated, water (20 ml) was added thereto and the mixture was adjusted to pH, 3-4 with diluted hydrochloric acid. The separated matter was collected by filtration and dried by heating in vacuo to provide 134 mg (yield 92%) of 7-acetyl-2-mercaptobenzooxazole as a dark solid. the mixture was heated to reflux for 16 hours The reaction was concentrated water (20 ml) was added The separated matter was collected by filtration dried by heating in vacuo

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

Procedure: A solution of crude 1-benzyl-1H-tetrazole-5-carbonyl chloride (prepared from 2.4 g of potassium 1-benzyl-1H-tetrazole-5-carboxylate in the manner hereinbefore described in Reference Example 3) in dry methylene chloride (50 ml) was added to a stirred solution of 3-amino-2-hydroxyacetophenone (1.5 g) and pyridine (0.9 g) in dry methylene chloride (40 ml) at 10° C. After standing at room temperature overnight, the solution was evaporated in vacuo and the resulting solid residue was recrystallised from a large volume of ethanol to give 3'-acetyl-1-benzyl-2'-hydroxy-1H-tetrazole-5-carboxanilide (1.5 g), in the form of pale yellow needles, m.p. 155°-157° C. the solution was evaporated in vacuo the resulting solid residue was recrystallised from a large volume of ethanol

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

Procedure: A solution of crude 1-benzyl-1H-tetrazole-5-carbonyl chloride (prepared from 2.4 g of potassium 1-benzyl-1H-tetrazole-5-carboxylate in the manner hereinbefore described in Reference Example 3) in dry methylene chloride (50 ml) was added to a stirred solution of 3-amino-2-hydroxyacetophenone (1.5 g) and pyridine (0.9 g) in dry methylene chloride (40 ml) at 10° C. After standing at room temperature overnight, the solution was evaporated in vacuo and the resulting solid residue was recrystallised from a large volume of ethanol to give 3'-acetyl-1-benzyl-2'-hydroxy-1H-tetrazole-5-carboxanilide (1.5 g), in the form of pale yellow needles, m.p. 155°-157° C. the solution was evaporated in vacuo the resulting solid residue was recrystallised from a large volume of ethanol

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

Procedure: A solution of 2-hydroxy-3-nitroacetophenone [4.0 g; prepared by the method of Allen et al., J. Chem. Soc., (1949), 821] in ethanol (150 ml) was hydrogenated at 25° C. and 50 p.s.i. for 2.5 hours, using a catalyst of platinum on charcoal. The mixture was filtered and the filtrate was evaporated in vacuo to give a black solid, which was purified by chromatography on a column of silica gel, using diethyl ether as eluant. The fastest moving band (yellow) was collected to give 3-amino-2-hydroxyacetophenone (3.0 g), in the form of a bright yellow solid, m.p. 95°-97° C. prepared by the method of Allen et al., J was hydrogenated at 25° C. The mixture was filtered the filtrate was evaporated in vacuo to give a black solid, which was purified by chromatography on a column of silica gel was collected

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

Procedure: A solution of 2-hydroxy-3-nitroacetophenone [4.0 g; prepared by the method of Allen et al., J. Chem. Soc., (1949), 821] in ethanol (150 ml) was hydrogenated at 25° C. and 50 p.s.i. for 2.5 hours, using a catalyst of platinum on charcoal. The mixture was filtered and the filtrate was evaporated in vacuo to give a black solid, which was purified by chromatography on a column of silica gel, using diethyl ether as eluant. The fastest moving band (yellow) was collected to give 3-amino-2-hydroxyacetophenone (3.0 g), in the form of a bright yellow solid, m.p. 95°-97° C. prepared by the method of Allen et al., J was hydrogenated at 25° C. The mixture was filtered the filtrate was evaporated in vacuo to give a black solid, which was purified by chromatography on a column of silica gel was collected

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

Procedure: Following the process described in example 1 (point K), starting from 6-chloro-2-(3-phenylpropyl)-2,3-dihydrobenzofuran-5-carboxylic acid and 3-amino-2-hydroxyacetophenone, the title compound was prepared, which was purified by chromatography through a silica gel column, eluting with hexane:ethyl acetate, 1:1 (42% yield). which was purified by chromatography through a silica gel column eluting with hexane

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

Procedure: Following the process described in example 1 (point K), starting from 4-chloro-2-(3-phenylpropyl)-2,3-dihydrobenzofuran-5-carboxylic acid and 3-amino-2-hydroxyacetophenone, the title compound was prepared (93% yield).