O-tert-butylhydroxylamine;hydrochloride

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

Procedure: To a solution of the compound prepared in Example 8(11) (1.00 g) in DMF (20 ml), t-butoxyamine hydrochloride (652 mg), triethylamine (0.8 ml), 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) hydrochloride (995 mg) and 1-hydroxybenzotriazole (HOBt) hydrate (795 mg) were added at 0° C. The mixture was stirred for 16 hours at room temperature. To the reaction mixture, ethyl acetate and water were added. The organic phase was washed with 0.1 N hydrochloric acid, a saturated aqueous solution of sodium bicarbonate, water and a saturated aqueous solution of sodium chloride, successively, dried over anhydrous magnesium sulfate and concentrated to give the title compound (1.35 g) having the following physical data. The organic phase was washed with 0.1 N hydrochloric acid a saturated aqueous solution of sodium bicarbonate, water and a saturated aqueous solution of sodium chloride, successively, dried over anhydrous magnesium sulfate concentrated

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

Procedure: O-tert-butylhydroxylamine hydrochloride (127 mg, 1.01 mmol), 1-(3-dimethylamino-propyl)-3-ethylcarbodiimide hydrochloride (129 mg, 0.67 mmol), N,N imethylaminopyridine (41 mg, 0.34 mmol), and N-methylmorpholine (0.15 ml, 1.3 mmol) were added to a solution of 1-[4-(4-chlorobenzoyl)piperidine-1-sulfonyl]piperidine-2-(R)-carboxylic acid (140 mg, 0.34 mmol), [prepared by proceeding as described in Example 9, but replacing D-valine and 4-(4-chlorophenoxy)piperidinesulfamoyl chloride with D-pipecolinic acid and 4-(4-chlorobenzoyl-piperidinesulfamoyl chloride, respectively], in methylene chloride (2 ml). After stirring overnight, the reaction mixture was diluted with ethyl acetate, washed with 1M HCl, and brine, and dried over MgSO4. The organics were evaporated in vacuo and the residue was chromatographed (FMLC, SiO2, 40% ethyl acetate/hexane) to give N-tert-butoxy-1-[4-(4-chlorobenzoyl)piperidine-1-sulfonyl]piperidine-2-(R)-carboxamide as a white solid (65%). [prepared washed with 1M HCl, and brine dried over MgSO4 The organics were evaporated in vacuo the residue was chromatographed (FMLC, SiO2, 40% ethyl acetate/hexane)

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

Procedure: To a solution of (+)-1-(4-methoxybenzenesulfonyl)-4-benzyloxycarbonyl-2-piperazinecarboxylic acid (100 mg, 0.23 mmol) in methylene chloride (5 ml) is added O-t-butylhydroxylamine hydrochloride (35 mg, 0.28 mmol), dimethylaminopyridine (37 mg, 0.30 mmol), and dicyclohexycarbodiimide (57 mg, 0.28 mmol). After stirring overnight, the reaction is diluted with hexanes and the precipitated solid filtered off. The solution is concentrated and the crude product is purified by silica gel chromatography (elution with 2:1 ethyl acetate-hexanes with 1% acetic acid) to provide (+)-N-(t-butyloxy)-1-(4-methoxybenzenesulfonyl)-4-benzyloxycarbonyl-2-piperazinecarboxamide. the precipitated solid filtered off The solution is concentrated the crude product is purified by silica gel chromatography (elution with 2:1 ethyl acetate-hexanes with 1% acetic acid)

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

Procedure: Benzo[b]-thien-2-ylglyoxylic acid (3.09 g) and t-butoxyamine hydrochloride (1.98 g) were dissolved in 50% aqueous ethanol (100 ml). The solution was adjusted to pH 4.5 with sodium hydroxide solution and maintained at such for 4 hr. at room temperature. Thin-layer chromatography showed incomplete reaction. t-Butoxyamine hydrochloride (500 mg.) was added and the solution kept at room temperature overnight. The alcohol was removed by evaporation and the aqueous phase adjusted to pH 8 and washed with ether. The aqueous phase was then acidified to pH 1.5 under ether. The ether solution was washed with water and dried. Evaporation gave a cream solid (4.05 g.). Fractional crystallisation from cyclohexane gave the anti-isomer of the title compound (1.6 g.). The mother liquors were combined and evaporated to give a cream solid (2.11 g.) that was treated in ether with excess diazomethane in ether at 0°-5°. The excess reagent was destroyed by acetic acid and the ether solution washed with sodium bicarbonate, water and dried. Evaporation gave an oil (1.75 g.). This was dissolved in methanol (70 ml) and treated with sodium hydroxide solution (N: 7 ml.) at room temperature for 3 hr. Hydrochloric acid (2N: 3.5 ml) was added and the methanol was removed by evaporation. The aqueous residue was partitioned between ether and sodium bicarbonate solution. The ether layer was washed with water and dried. Evaporation gave an oil (0.92 g.) that was dissolved in methanol (20 ml.) and treated with sodium hydroxide (N: 7 ml) at reflux temperature for 3hr. Sodium hydroxide (N: 5ml) was added and the solution refluxed for 6 hr. The methanol was removed by evaporation and the residue partitioned between ether and water. The aqueous phase was acidified (pH 1.5) under ether and the ether layer washed with water, dried and evaporated to give a pale orange crystalline solid (760 mg. 18%). Crystallisation from benzene containing cyclohexane gave syn-2-t-butoxyimino-2-(benzo[b]-thien-2-yl)acetic acid (430 mg.) m.p. 108°-9°, λmax. (EtOH) 231, 253, 297 nm (ε17,000, 7,240, 24,500). maintained at such for 4 hr at room temperature reaction The alcohol was removed by evaporation washed with ether The ether solution was washed with water dried Evaporation gave a cream solid (4.05 g.) Fractional crystallisation from cyclohexane

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

Procedure: A solution of thien-2-ylglyoxylic acid (6.2g.) and sodium bicarbonate (3.36g.) in water (100 ml.) was added dropwise to a stirred solution of t-butoxyamine hydrochloride (5.65 g.) and sodium bicarbonate (3.78g.) in water (100 ml.) at 0°-5° and the mixture was stirred at room temperature for 18 hr. The mixture was acidified with 2N hydrochloric acid to pH 2.0 and extracted with ethyl acetate. The combined extracts were washed with water, dried and concentrated to give a solid (9.75 g.). Recrystallisation from petroleum (b.p. 60°-80°) gave the title compound (4.0 g., 44%), m.p. 106°-107°, λmax. (EtOH) 290 nm (ε11,600), τ (CDCl3) values include 2.46, 2.66, 2.98 (d doublets, thienyl protons), 8.60 (C(CH3)3). extracted with ethyl acetate The combined extracts were washed with water dried concentrated to give a solid (9.75 g.) Recrystallisation from petroleum (b.p. 60°-80°)

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

Procedure: O-tert-Butylhydroxylamine hydrochloride (3.0 g, 23.9 mmol) was added to 4-bromo-1,8-naphthalic anhydride (5.0 g, 18.0 mmol) in pyridine (30.0 mL). The mixture was refluxed for 4 hours, concentrated, and the residue suspended in water. The solid was filtered and dried to give 5.9 g of the title compound. The mixture was refluxed for 4 hours concentrated The solid was filtered dried

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

Procedure: O-tert-Butylhydroxylamine hydrochloride (3.0 g, 23.9 mmol) was added to 4-bromo-1,8-naphthalic anhydride (5.0 g, 18.0 mmol) in pyridine (30.0 mL). The mixture was refluxed for 4 hours, concentrated, and the residue suspended in water. The solid was filtered and dried to give 5.9 g of the title compound. The mixture was refluxed for 4 hours concentrated The solid was filtered dried

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

Procedure: 2(R)-[[4-Methoxybenzenesulfonyl](4-picolyl)amino]-cyclohexylacetic acid hydrochloride (1.8 g, 4.2 mmol), 1-hydroxybenzotriazole (0.65 g, 4.81 mmol), 4-methyl-morpholine (2.4 mL, 24.04 mmol), and O-t-butylhydroxylamine hydrochloride (1.81 g, 14.4 mmol) are dissolved in methylene chloride (100 mL). N-[dimethylaminopropyl]-N'-ethyl-carbodiimide hydrochloride (1.2 g, 6.25 mmol) is added, and the reaction is stirred overnight. The reaction is then diluted with water and extracted with methylene chloride. The combined organic extracts are washed with brine, dried (Na2SO4), and the solvent is evaporated. The crude product is purified by silica gel chromatography (5% methanol/methylene chloride) to give N-(t-butyloxy)-2(R)-[[4-methoxybenzenesulfonyl]-(4-picolyl)amino]-2-cyclohexylacetamide. extracted with methylene chloride The combined organic extracts are washed with brine dried (Na2SO4) the solvent is evaporated The crude product is purified by silica gel chromatography (5% methanol/methylene chloride)

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

Procedure: 2(R)-[[4-Methoxybenzenesulfonyl](4-picolyl)amino]-cyclohexylacetic acid hydrochloride (1.8 g, 4.2 mmol), 1-hydroxybenzotriazole (0.65 g, 4.81 mmol), 4-methyl-morpholine (2.4 mL, 24.04 mmol), and O-t-butylhydroxylamine hydrochloride (1.81 g, 14.4 mmol) are dissolved in methylene chloride (100 mL). N-[dimethylaminopropyl]-N'-ethyl-carbodiimide hydrochloride (1.2 g, 6.25 mmol) is added, and the reaction is stirred overnight. The reaction is then diluted with water and extracted with methylene chloride. The combined organic extracts are washed with brine, dried (Na2SO4), and the solvent is evaporated. The crude product is purified by silica gel chromatography (5% methanol/methylene chloride) to give N-(t-butyloxy)-2(R)-[[4-methoxybenzenesulfonyl]-(4-picolyl)amino]-2-cyclohexylacetamide. extracted with methylene chloride The combined organic extracts are washed with brine dried (Na2SO4) the solvent is evaporated The crude product is purified by silica gel chromatography (5% methanol/methylene chloride)

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

Procedure: N-[4-methoxybenzenesulfonyl]-(D)-threonine (4.0 g, 13.84 mmol), 1-hydroxybenzotriazole (1.87 g, 13.84 mmol), 4-methylmorpholine (7.9 mL, 69.2 mmol), and O-t-butyl-hydroxylamine hydrochloride (5.22 g, 41.52 mmol) are dissolved in methylene chloride (100 mL). To this solution is added N-[dimethylaminopropyl]-N'-ethylcarbodiimide hydrochloride (3.45 g, 17.99 mmol), and the reaction is stirred overnight. The mixture is then diluted with water and extracted with methylene chloride. The combined organic extracts are washed with brine, dried (Na2SO4), and concentrated in vacuo. The crude product is purified by silica gel chromatography (ethyl acetate) to give N-(t-butyloxy)-2(R)-[[4-methoxybenzenesulfonyl]-amino]-3(R)-hydroxybutanamide. extracted with methylene chloride The combined organic extracts are washed with brine dried (Na2SO4) concentrated in vacuo The crude product is purified by silica gel chromatography (ethyl acetate)

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

Procedure: N-[4-methoxybenzenesulfonyl]-(D)-threonine (4.0 g, 13.84 mmol), 1-hydroxybenzotriazole (1.87 g, 13.84 mmol), 4-methylmorpholine (7.9 mL, 69.2 mmol), and O-t-butyl-hydroxylamine hydrochloride (5.22 g, 41.52 mmol) are dissolved in methylene chloride (100 mL). To this solution is added N-[dimethylaminopropyl]-N'-ethylcarbodiimide hydrochloride (3.45 g, 17.99 mmol), and the reaction is stirred overnight. The mixture is then diluted with water and extracted with methylene chloride. The combined organic extracts are washed with brine, dried (Na2SO4), and concentrated in vacuo. The crude product is purified by silica gel chromatography (ethyl acetate) to give N-(t-butyloxy)-2(R)-[[4-methoxybenzenesulfonyl]-amino]-3(R)-hydroxybutanamide. extracted with methylene chloride The combined organic extracts are washed with brine dried (Na2SO4) concentrated in vacuo The crude product is purified by silica gel chromatography (ethyl acetate)

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

Procedure: 2(R)-[[4-methoxybenzenesulfonyl](3-picolyl)amino]-3-methylbutanoic acid hydrochloride is reacted with O-benzylhydroxylamine hydrochloride under conditions described for reaction with O-t-butylhydroxylamine hydrochloride to yield N-(benzyloxy)-2(R)-[[4-methoxybenzenesulfonyl](3-picolyl)amino]-3-methyl-butanamide, m.p. 74.5°-76° C.