tert-butyl 2-aminooxyacetate

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: In 1.35 l of dichloromethane is dissolved 37.4 g (0.135 mole) of N-(tert-butoxycarbonylmethoxy) phthalimide, and 9.21 ml (0.189 mole) of hydrazine hydrate is added dropwise to the solution over the period of 10 minutes, followed by stirring at room temperature for 2 hours. 3.95 ml (0.081 mole) of hydrazine hydrate is furthermore added, followed by stirring for further 1.5 hours. The reaction solution is filtered, and the filtrate is washed with 300 ml of 2N ammonium water and aqueous sodium chloride solution successively, and dried over anhydrous sodium sulfate. The solvent is distilled off under reduced pressure to give 18.95 g (95.4%) of O-(tert-butoxycarbonylmethyl)hydroxylamine as a yellow oily product. is added dropwise to the solution over the period of 10 minutes by stirring for further 1.5 hours The reaction solution is filtered the filtrate is washed with 300 ml of 2N ammonium water and aqueous sodium chloride solution successively dried over anhydrous sodium sulfate The solvent is distilled off under reduced pressure

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

Procedure: To a solution of (1,2,5-thiadiazol-3-yl)glyoxylic acid (6 g) in tetrahydrofuran (30 ml) and water (30 ml) was added tert-butoxycarbonylmethoxyamine (8.37 g) at ambient temperature. The mixture was adjusted to pH 4.5-5.0 with 4N aqueous sodium hydroxide and stirred at ambient temperature for 4 hours. The mixture was adjusted to pH 7.5 with 4N aqueous sodium hydroxide and washed with ethyl acetate (100 ml×2). The aqueous solution was acidified to pH 2.0 with 10% hydrochloric acid and extracted with ethyl acetate (100 ml×2). The organic layer was washed with an aqueous sodium chloride and dried over magnesium sulfate. The solution was evaporated in vacuo to give 2-tert-butoxycarbonylmethoxyimino-2-(1,2,5-thiadiazol-3-yl)acetic acid (syn and anti mixture) (10.02 g). washed with ethyl acetate (100 ml×2) extracted with ethyl acetate (100 ml×2) The organic layer was washed with an aqueous sodium chloride dried over magnesium sulfate The solution was evaporated in vacuo

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

Procedure: To a solution of (2S,5R)-6-(benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octane-2-carboxylic acid 1 (0.20 g, 0.72 mmol) in dry DCM (20 mL) were added tert-butyl (aminooxy)acetate 88 (0.13 g, 0.86 mmol, Organic Letters, 2002, 4(6) 869-872), 1-hydroxybenzotriazole (0.15 g, 1.11 mmol) and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.21 g, 1.10 mmol) at room temperature. The reaction mixture was stirred at room temperature overnight and concentrated under vacuum. The residue was purified by column chromatography to give tert-butyl [({[(2S,5R)-6-(benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]oct-2-yl]carbonyl}amino)oxy]acetate 89 (0.23 g, 79%) as a white solid. concentrated under vacuum The residue was purified by column chromatography

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

Procedure: A solution of N-t-butoxycarbonylmethoxyphthalimide (21g) in methylene chloride (250ml) was treated with 100% hydrazine hydrate (7.6ml) in methanol (15ml), and the mixture was stirred for 1.5 hr. 5N-Ammonia solution was added to dissolve the precipitated solid. The organic layer was separated, and the aqueous layer was further extracted with methylene chloride. The combined extracts were washed with water, dried, and evaporated to give a pale-yellow solid. To this was added ether, the mixture was filtered, and the filtrate evaporated to give t-butoxycarbonylmethoxyamine as a pale yellow liquid, (8.88g, 80%); νmax. (Nujol) includes 3330, 3260 cm.-1 (NH2), 1742 cm.-1 (-COOBut); τ values (DMSO-d6) are 3.75 (-NH2), 5.96 (CH2) 8.55 (But). to dissolve the precipitated solid The organic layer was separated the aqueous layer was further extracted with methylene chloride The combined extracts were washed with water dried evaporated to give a pale-yellow solid the mixture was filtered the filtrate evaporated

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

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

Procedure: A mixture of 2-(3-chloro-4-hydroxyphenyl)glyoxylic acid (2.0 g.), O-t-butoxycarbonylmethylhydroxylamine (1.62 g.) and methanol (20 ml.) was adjusted to pH 5 to 6 by adding an 1 N methanol solution of sodium methoxide and stirred for 3 hours at ambient temperature. The reaction mixture was concentrated to dryness under reduced pressure and the residue was dissolved in an 1 N aqueous solution of sodium hydroxide to adjust to pH 7.0. The aqueous solution was washed with ether, adjusted to pH 2.0 with 10% hydrochloric acid under ice-cooling and extracted with ether. The extract was washed with water and dried over magnesium sulfate. The solution was concentrated to dryness under reduced pressure to give crystals of 2-t-butoxycarbonylmethoxyimino-2-(3-chloro-4-hydroxyphenyl)acetic acid (syn isomer) (2.6 g.), mp 116° to 118° C. (dec.). The reaction mixture was concentrated to dryness under reduced pressure the residue was dissolved in an 1 N aqueous solution of sodium hydroxide The aqueous solution was washed with ether cooling extracted with ether The extract was washed with water dried over magnesium sulfate The solution was concentrated to dryness under reduced pressure

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

Procedure: A mixture of 2-(3-chloro-4-hydroxyphenyl)glyoxylic acid (2.0 g.), O-t-butoxycarbonylmethylhydroxylamine (1.62 g.) and methanol (20 ml.) was adjusted to pH 5 to 6 by adding an 1 N methanol solution of sodium methoxide and stirred for 3 hours at ambient temperature. The reaction mixture was concentrated to dryness under reduced pressure and the residue was dissolved in an 1 N aqueous solution of sodium hydroxide to adjust to pH 7.0. The aqueous solution was washed with ether, adjusted to pH 2.0 with 10% hydrochloric acid under ice-cooling and extracted with ether. The extract was washed with water and dried over magnesium sulfate. The solution was concentrated to dryness under reduced pressure to give crystals of 2-t-butoxycarbonylmethoxyimino-2-(3-chloro-4-hydroxyphenyl)acetic acid (syn isomer) (2.6 g.), mp 116° to 118° C. (dec.). The reaction mixture was concentrated to dryness under reduced pressure the residue was dissolved in an 1 N aqueous solution of sodium hydroxide The aqueous solution was washed with ether cooling extracted with ether The extract was washed with water dried over magnesium sulfate The solution was concentrated to dryness under reduced pressure