3,4-dihydro-2H-1-benzoxepin-5-one

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: A solution of 10.0 g (62 mmol) of 3,4-dihydro-1-benzoxepin-5(2H)-one (J. Chem. Soc., Perkin Trans. 1 (1991), 2763) and 4.63 g (68 mmol) of hydroxylamine hydrochloride in 45 ml of ethanol and 45 ml of pyridine was heated under reflux for 5 h. After distilling off the solvents on a rotary evaporator, the residue was treated with water, adjusted to pH 2 with dil hydrochloric acid and stirred for 3 h. After filtering off the precipitated product with suction and drying it, 10.2 g of 3,4-dihydro-1-benzoxepin-5(2H)-one oxime were obtained, m.p. 96-98° C. b) A solution of 2.0 g (11.3 mmol) of 3,4-dihydro-1-benzoxepin-5(2H)-one oxime in 15 ml of 1,2-dimethoxyethane (DME) was added dropwise at 0° C. under argon to a mixture of 4.5 g (23.7 mmol) of titanium tetrachloride and 1.79 g (47.4 mmol) of sodium borohydride in 50 ml of DME over the course of 20 min. After stirring at RT for 2 days, 100 ml of water were added dropwise and the mixture was rendered alkaline using conc. ammonia solution. After filtering off the precipitate with suction, the filtrate was extracted three times with EA. After washing with sodium chloride solution, drying over magnesium sulfate and concentrating, 2.1 g of 5-amino-2,3,4,5-tetrahydro-1-benzoxepine were obtained. c) 0.86 g (6.7 mmol) of ethanesulfonyl chloride was added dropwise with ice cooling to a solution of 1.0 g (6.1 mmol) of 5-amino-2,3,4,5-tetrahydro-1-benzoxepine and 2.5 g (24 mmol) of triethylamine in 20 ml of THF. The mixture was allowed to come to room temperature and was stirred overnight, and the solvent was distilled off in vacuo. After stirring the residue with water, the deposited product was filtered off with suction. 1.1 g of 5-ethylsulfonylamino-2,3,4,5-tetrahydro-1-berzoxepine were obtained, m.p. 109-111° C. d) A solution of 1.0 g (3.9 mmol) of 5-ethylsulfonylamino-2,3,4,5-tetrahydro-1-benzoxepine in 15 ml of THF were added dropwise under nitrogen to a suspension of 0.16 g (5.4 mmol) of 80 percent sodium hydride in 10 ml of THF. After stirring at RT for 3 h, 1.6 g (11 mmol) of methyl iodide were added dropwise and the mixture was additionally stirred overnight at RT. After distilling off the solvent, the residue was treated with water and extracted with EA. The organic phase was concentrated in vacuo after drying over sodium sulfate. 1.0 g of 5-(N-ethylsulfonyl-N-methylamino)-2,3,4,5-tetrahydro-1-benzoxepine was obtained, m.p. 122-124° C. under reflux for 5 h After distilling off the solvents on a rotary evaporator the residue was treated with water After filtering off the precipitated product with suction drying it

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

Procedure: To a solution of 3,4-dihydro-2H-benzo[b]oxepin-5-one (3.10 g, 12.8 mmol) in diethyl ether at 0° C., bromine (625 μl, 12.2 mmol) was added and stirred for 2.5 hours, gradually raising the temperature to room temperature. Purification on silica and triturating using diethyl ether and hexanes gave 4-bromo-3,4-dihydro-2H-benzo[b]oxepin-5-one. Purification on silica triturating

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

Procedure: To a solution of phenol (3.16 g, 33.6 mmol) in acetonitrile, was added ethyl 4-bromobutyrate (4.8 ml, 33.6 mmol), potassium carbonate (4.64 g, 33.6 mmol) and tetrabutylammonium iodide (370 mg, 1 mmol). The reaction mixture was stirred vigorously and heated to reflux for 2 days before being cooled, filtered, dried (MgSO4) and concentrated in-vacuo to yield 4-phenoxy-butyric acid ethyl ester. 4-Phenoxy-butyric acid ethyl ester was hydrolyzed to its corresponding carboxylic acid using sodium hydroxide mediated hydrolysis to yield 4-phenoxy-butyric acid. To a solution of 4-phenoxy-butyric acid (7.67 g, 29.6 mmol) in anhydrous dichloromethane was added oxalyl chloride (4.4 ml, 50.3 mmol) and one drop of dimethyl formamide and the reaction mixture stirred at room temperature for 30 minutes. Reaction mixture was concentrated in-vacuo and the residue dissolved in 1,2-dichloroethane (90 ml). This solution was added drop wise to a suspension of aluminum trichloride (4.73 g, 35.5 mmol) in 1,2-dichloroethane (50 ml) at 0° C. Reaction mixture was left stirring in ice bath which rose to room temperature overnight. The reaction mixture was poured over conc. hydrochloric acid (30 ml) stirred into 100 g ice, and then stirred for a further 90 minutes until the ice fully melted. The aqueous phase was washed with dichloromethane 3 times, before the organics were combined, dried (Na2SO4) and concentrated in-vacuo. Purification by triturating with diethyl ether gave 3,4-dihydro-2H-benzo[b]oxepin-5-one. Reaction mixture was concentrated in-vacuo the residue dissolved in 1,2-dichloroethane (90 ml) This solution was added drop Reaction mixture was left stirring in ice bath which rose to room temperature overnight The aqueous phase was washed with dichloromethane 3 times dried (Na2SO4) concentrated in-vacuo Purification by triturating with diethyl ether

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

Procedure: To a solution of phenol (3.16 g, 33.6 mmol) in acetonitrile, was added ethyl 4-bromobutyrate (4.8 ml, 33.6 mmol), potassium carbonate (4.64 g, 33.6 mmol) and tetrabutylammonium iodide (370 mg, 1 mmol). The reaction mixture was stirred vigorously and heated to reflux for 2 days before being cooled, filtered, dried (MgSO4) and concentrated in-vacuo to yield 4-phenoxy-butyric acid ethyl ester. 4-Phenoxy-butyric acid ethyl ester was hydrolyzed to its corresponding carboxylic acid using sodium hydroxide mediated hydrolysis to yield 4-phenoxy-butyric acid. To a solution of 4-phenoxy-butyric acid (7.67 g, 29.6 mmol) in anhydrous dichloromethane was added oxalyl chloride (4.4 ml, 50.3 mmol) and one drop of dimethyl formamide and the reaction mixture stirred at room temperature for 30 minutes. Reaction mixture was concentrated in-vacuo and the residue dissolved in 1,2-dichloroethane (90 ml). This solution was added drop wise to a suspension of aluminum trichloride (4.73 g, 35.5 mmol) in 1,2-dichloroethane (50 ml) at 0° C. Reaction mixture was left stirring in ice bath which rose to room temperature overnight. The reaction mixture was poured over conc. hydrochloric acid (30 ml) stirred into 100 g ice, and then stirred for a further 90 minutes until the ice fully melted. The aqueous phase was washed with dichloromethane 3 times, before the organics were combined, dried (Na2SO4) and concentrated in-vacuo. Purification by triturating with diethyl ether gave 3,4-dihydro-2H-benzo[b]oxepin-5-one. Reaction mixture was concentrated in-vacuo the residue dissolved in 1,2-dichloroethane (90 ml) This solution was added drop Reaction mixture was left stirring in ice bath which rose to room temperature overnight The aqueous phase was washed with dichloromethane 3 times dried (Na2SO4) concentrated in-vacuo Purification by triturating with diethyl ether

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

Procedure: Scheme 2 shows a general method of preparation of N,N-disubstituted 4,5-dihydrobenzo[b]thieno[2,3-d]oxepine-2-carboxamide intermediates 69. 3,4-Dihydrobenzo[b]oxepin-5(2H)-one intermediates 66 are formylated with phosphorus oxytrichloride and dimethylformamide (DMF) to give 5-chloro-2,3-dihydrobenzo[b]oxepine-4-carbaldehyde intermediate 70. Cyclization of 70 with a mercapto acetate ester (HSCH2CO2R where R is alkyl or aryl) in potassium carbonate and DMF gives the 4,5-dihydrobenzo[b]thieno[2,3-d]oxepine-2-carboxylate ester intermediate 71. Saponification of 71 with lithium hydroxide in THF and water gives the acid (R═H) which is treated with thionyl chloride at reflux followed by a secondary amine (HNR5R6), such as N-methyl-2-chloroaniline, with a catalytic amount of DMAP (4,4-dimethylaminopyridine), triethylamine, and dichloromethane to give 4,5-dihydrobenzo[b]thieno[2,3-d]oxepine-2-carboxamide intermediates 69. Alternatively, the acid is treated with oxalyl chloride and a catalytic amount of DMF to generate the acid chloride, followed by reaction with the amine and potassium carbonate in acetonitrile to give amides such as 69. Where one of R1, R2, R3, or R4 is bromo, the bromine of 69, or of another intermediate such as 66, 70, 71, may be displaced by: (i) carbonylative amination to give amide (—NR12C(═O)R10, (ii) formylation (—CHO) followed by reductive amination to —CH2NR10R11, (iii) Suzuki coupling with aryl or heteroaryl, (iv) Sonagoshira coupling to give alkynyl (—C═CR10), or (v) amination (—NR10R11).

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

Procedure: Scheme 1 shows a general method for preparation of 3,4-dihydrobenzo[b]oxepin-5(2H)-one intermediates 66 by O-alkylation of a phenolic compound with ethyl 4-bromobutanoate to give a ethyl 4-phenoxybutanoate intermediate 67, followed by saponification to the carboxylic acid 68 and intramolecular cyclization under acidic conditions.

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

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

Procedure: Scheme 2 shows a general method of preparation of N,N-disubstituted 4,5-dihydrobenzo[b]thieno[2,3-d]oxepine-2-carboxamide intermediates 69. 3,4-Dihydrobenzo[b]oxepin-5(2H)-one intermediates 66 are formylated with phosphorus oxytrichloride and dimethylformamide (DMF) to give 5-chloro-2,3-dihydrobenzo[b]oxepine-4-carbaldehyde intermediate 70. Cyclization of 70 with a mercapto acetate ester (HSCH2CO2R where R is alkyl or aryl) in potassium carbonate and DMF gives the 4,5-dihydrobenzo[b]thieno[2,3-d]oxepine-2-carboxylate ester intermediate 71. Saponification of 71 with lithium hydroxide in THF and water gives the acid (R═H) which is treated with thionyl chloride at reflux followed by a secondary amine (HNR5R6), such as N-methyl-2-chloroaniline, with a catalytic amount of DMAP (4,4-dimethylaminopyridine), triethylamine, and dichloromethane to give 4,5-dihydrobenzo[b]thieno[2,3-d]oxepine-2-carboxamide intermediates 69. Alternatively, the acid is treated with oxalyl chloride and a catalytic amount of DMF to generate the acid chloride, followed by reaction with the amine and potassium carbonate in acetonitrile to give amides such as 69. Where one of R1, R2, R3, or R4 is bromo, the bromine of 69, or of another intermediate such as 66, 70, 71, may be displaced by: (i) carbonylative amination to give amide (—NR12C(═O)R10, (ii) formylation (—CHO) followed by reductive amination to —CH2NR10R11, (iii) Suzuki coupling with aryl or heteroaryl, (iv) Sonagoshira coupling to give alkynyl (—C≡CR10), or (v) amination (—NR10R11).

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

Procedure: Scheme 1 shows a general method for preparation of 3,4-dihydrobenzo[b]oxepin-5(2H)-one intermediates 66 by O-alkylation of a phenolic compound with ethyl 4-bromobutanoate to give a ethyl 4-phenoxybutanoate intermediate 67, followed by saponification to the carboxylic acid 68 and intramolecular cyclization under acidic conditions.

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

Procedure: To a solution of 3,4-dihydro-2H-benzo[b]oxepin-5-one (3.10 g, 12.8 mmol) in diethyl ether at 0° C., bromine (625 μl, 12.2 mmol) was added and stirred for 2.5 hours, gradually raising the temperature to room temperature. Purification on silica and triturating using diethyl ether and hexanes gave 4-bromo-3,4-dihydro-2H-benzo[b]oxepin-5-one. Purification on silica triturating