(2S)-1-[(2-methylpropan-2-yl)oxycarbonyl]azetidine-2-carboxylic acid

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

Procedure: (S)-1-(tert-butoxycarbonyl)-2-azetidinecarboxylic acid (10.42 g, 49.4 mmol) was introduced into a 500-mL pear-shaped flask, and tetrahydrofuran (200 mL) was added to dissolve the compound. Then, a tetrahydrofuran solution of 10 M borane-dimethyl sulfide complex salt (9.87 mL, 98.7 mmol) was slowly added at 0° C., and the mixture was heated to reflux for 2 hours while stirring. The reaction solution was left to cool, and then was concentrated under reduced pressure. Ice water (100 mL) was poured thereto, and the mixture was extracted with ethyl acetate (200 mL×2). The extract was washed with saturated brine (200 mL), and then dried over anhydrous sodium sulfate. After filtering the extract, the filtrate was concentrated under reduced pressure to obtain the title compound (8.03 g, 42.9 mmol, 87%) as an oily matter. to dissolve the compound the mixture was heated to reflux for 2 hours The reaction solution was left to cool was concentrated under reduced pressure Ice water (100 mL) was poured the mixture was extracted with ethyl acetate (200 mL×2) The extract was washed with saturated brine (200 mL) dried over anhydrous sodium sulfate After filtering the extract the filtrate was concentrated under reduced pressure

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

Procedure: (S)-1-(tert-butoxycarbonyl)-2-azetidinecarboxylic acid (10.42 g, 49.4 mmol) was introduced into a 500-mL pear-shaped flask, and tetrahydrofuran (200 mL) was added to dissolve the compound. Then, a tetrahydrofuran solution of 10 M borane-dimethyl sulfide complex salt (9.87 mL, 98.7 mmol) was slowly added at 0° C., and the mixture was heated to reflux for 2 hours while stirring. The reaction solution was left to cool, and then was concentrated under reduced pressure. Ice water (100 mL) was poured thereto, and the mixture was extracted with ethyl acetate (200 mL×2). The extract was washed with saturated brine (200 mL), and then dried over anhydrous sodium sulfate. After filtering the extract, the filtrate was concentrated under reduced pressure to obtain the title compound (8.03 g, 42.9 mmol, 87%) as an oily matter. to dissolve the compound the mixture was heated to reflux for 2 hours The reaction solution was left to cool was concentrated under reduced pressure Ice water (100 mL) was poured the mixture was extracted with ethyl acetate (200 mL×2) The extract was washed with saturated brine (200 mL) dried over anhydrous sodium sulfate After filtering the extract the filtrate was concentrated under reduced pressure

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

Procedure: A mixed solution of tetrahydrofuran (70 ml)/water (60 ml) containing (S)-N-(tert-butoxycarbonyl)azetidine-2-carboxylic acid (20.51 g; also containing (R)-isomer) and sulfuric acid (10.03 g) was stirred for 1 hour under ice cooling, 1.5 hours at room temperature, and for 28 hours under heating at 45 to 48° C. On the way, 6 N hydrochloric acid (20 ml) was further added after about 20 hours. The reaction mixture was cooled with ice, and sodium carbonate (38.92 g), 2-nitrobenzenesulfonyl chloride (29.42 g), tetrahydrofuran (50 ml) and water (60 ml) were added in turn thereto, followed by stirring for 70 minutes under ice cooling and for 37 hours at room temperature. On the way, sodium carbonate (5.45 g) was further added after 30 minutes. Water (140 ml) was added to the reaction mixture, and the organic solvent was removed by evaporation under reduced pressure. Then, water (40 ml) and ethyl acetate (140 ml) were added, followed by extraction and solution separation, and the organic layer was extracted again with water (100 ml). Ethyl acetate (30 ml) and concentrated hydrochloric acid (40 ml) were added to the resulting aqueous layer, and ethyl acetate (100 ml) was further added, followed by extraction and solution separation. The aqueous layer was extracted again with ethyl acetate (120 ml). The resulting organic layer was dried over sodium sulfate, filtered, concentrated and dried under vacuum to obtain (S)-N-(2-nitrobenzenesulfonyl)azetidine-2-carboxylic acid (26.2 g; yield: 89.8%). Analysis according to high performance liquid chromatography (HPLC) resulted in 46.4% ee. for 28 hours under heating at 45 to 48° C were added in turn by stirring for 70 minutes under ice cooling and for 37 hours at room temperature the organic solvent was removed by evaporation under reduced pressure Then, water (40 ml) and ethyl acetate (140 ml) were added followed by extraction and solution separation the organic layer was extracted again with water (100 ml) Ethyl acetate (30 ml) and concentrated hydrochloric acid (40 ml) were added to the resulting aqueous layer, and ethyl acetate (100 ml) was further added followed by extraction and solution separation The aqueous layer was extracted again with ethyl acetate (120 ml) The resulting organic layer was dried over sodium sulfate filtered concentrated dried under vacuum

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

Procedure: 2.00 g 1-Tert.butoxycarbonyl-azetidin-2(S)-carboxylic acid, 1.70 g 1-amino-6-aminomethyl-isoquinolin, 3.50 g TBTU were dissolved in 40 mL DMF. 3.55 mL N-methylmorpholin was added slowly with stirring. The solution was applied to a reversed-phase chromatography column (length 100 mm, diameter 14 mm; Merck Lichroprep RP-18, 15-25 μ). Elution was started with 25 mL of methanol/water containing 0.3% acetic acid (10:90), then a linear gradient to pure methanol over a period of 75 mL was applied followed by 50 mL of pure methanol. Fraktions of 5 mL each were sampled. The solvent was evaporated to give 3.4 g of the tile compound. MS: 357. Elution a linear gradient to pure methanol over a period of 75 mL was applied followed by 50 mL of pure methanol Fraktions of 5 mL each were sampled The solvent was evaporated

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

Procedure: N-Methylmorpholine (1.35 ml, 12 mmol) was added to a stirred solution of (S)-azetidine-2-carboxylic acid (1.08 g; 10 mmol) and di-tert-butyl-dicarbonate (3.03 g; 14 mmol) in 1,4-dioxane: water (1:1, 30 ml) cooled to 0° C. The system was allowed to stir for 18 h with the temperature being allowed to rise slowly to room temperature. Saturated sodium bicarbonate solution (15 ml), cooled to 5° C. was added and the system was washed with ethyl acetate (3×75 ml). The aqueous phase was then acidified to pH 3 by the addition of potassium hydrogen sulfate. The aqueous phase was then extracted with ethyl acetate (3×100 ml), these organic layers were combined, dried (MgSO4), filtered and solvent removed in vacuo to give the product (S)-N-tert-butoxycarbonyl-azetidine-2-carboxylic acid (2.15 g) as a viscous oil. EIMS: m/z=201 (M+H)+. Borane-THF complex (1M sol, 35 ml, 35 mmol) was added slowly to a stirred solution of the above carboxylic acid in dry tetrahydrofuran cooled to <5° C. under nitrogen. The reaction was allowed to stir for 18 h, with the temperature being allowed to slowly rise to room temperature. 10% Aqueous potassium hydrogen sulfate (10 ml) was then added dropwise. Volatile components were evaporated in vacuo and the remaining slurry was extracted with ethyl acetate (3×75 ml). The combined organic phase was dried (MgSO4), filtered and solvent removed in vacuo to give the product (S)-N-tert-Butoxycarbonyl-2-hydroxymethylazetidine as a viscous oil (1.48 g, 74%), m/z [M+Na]+ 210. cooled to <5° C. under nitrogen to slowly rise to room temperature Volatile components were evaporated in vacuo the remaining slurry was extracted with ethyl acetate (3×75 ml) The combined organic phase was dried (MgSO4) filtered solvent removed in vacuo

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

Procedure: N-Methylmorpholine (1.35 ml, 12 mmol) was added to a stirred solution of (S)-azetidine-2-carboxylic acid (1.08 g; 10 mmol) and di-tert-butyl-dicarbonate (3.03 g; 14 mmol) in 1,4-dioxane: water (1:1, 30 ml) cooled to 0° C. The system was allowed to stir for 18 h with the temperature being allowed to rise slowly to room temperature. Saturated sodium bicarbonate solution (15 ml), cooled to 5° C. was added and the system was washed with ethyl acetate (3×75 ml). The aqueous phase was then acidified to pH 3 by the addition of potassium hydrogen sulfate. The aqueous phase was then extracted with ethyl acetate (3×100 ml), these organic layers were combined, dried (MgSO4), filtered and solvent removed in vacuo to give the product (S)-N-tert-butoxycarbonyl-azetidine-2-carboxylic acid (2.15 g) as a viscous oil. EIMS: m/z=201 (M+H)+. Borane-THF complex (1M sol, 35 ml, 35 mmol) was added slowly to a stirred solution of the above carboxylic acid in dry tetrahydrofuran cooled to <5° C. under nitrogen. The reaction was allowed to stir for 18 h, with the temperature being allowed to slowly rise to room temperature. 10% Aqueous potassium hydrogen sulfate (10 ml) was then added dropwise. Volatile components were evaporated in vacuo and the remaining slurry was extracted with ethyl acetate (3×75 ml). The combined organic phase was dried (MgSO4), filtered and solvent removed in vacuo to give the product (S)-N-tert-Butoxycarbonyl-2-hydroxymethylazetidine as a viscous oil (1.48 g, 74%), m/z [M+Na]+ 210. cooled to <5° C. under nitrogen to slowly rise to room temperature Volatile components were evaporated in vacuo the remaining slurry was extracted with ethyl acetate (3×75 ml) The combined organic phase was dried (MgSO4) filtered solvent removed in vacuo

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

Procedure: A mixture of Boc-Aze-OH (5 g, 25 mmol) and HOSu (2.88 g, 25 mmol) in 25 ml of THF was cooled on an ice bath EDC (4.3 ml, 25 mmol) was added and the solution was stirred overnight. It was evaporated, dissolved in ethyl acetate, washed with KHSO4 (aq, 0.3 M), Na2CO3 (aq, 10%), dried (MgSO4) and evaporated. Crystallization from ethyl acetate:petroleum ether afforded 3.78 g (51%) of sub-title compound. was added It was evaporated dissolved in ethyl acetate washed with KHSO4 (aq, 0.3 M), Na2CO3 (aq, 10%) dried (MgSO4) evaporated Crystallization from ethyl acetate

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

Procedure: A mixture of Boc-Aze-OH (5 g, 25 mmol) and HOSu (2.88 g, 25 mmol) in 25 ml of THF was cooled on an ice bath EDC (4.3 ml, 25 mmol) was added and the solution was stirred overnight. It was evaporated, dissolved in ethyl acetate, washed with KHSO4 (aq, 0.3 M), Na2CO3 (aq, 10%), dried (MgSO4) and evaporated. Crystallization from ethyl acetate:petroleum ether afforded 3.78 g (51%) of sub-title compound. was added It was evaporated dissolved in ethyl acetate washed with KHSO4 (aq, 0.3 M), Na2CO3 (aq, 10%) dried (MgSO4) evaporated Crystallization from ethyl acetate

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

Procedure: The titled compound was prepared from N-(3,3-dimethyl-2,3-dihydro-1H-indol-6-yl)-2-[(1H-pyrrolo[2,3-b]pyridin-4-ylmethyl)amino]nicotinamide (Example 16) and (2S)-azetidine-1,2-dicarboxylic acid-1-tert-butyl ester by the method described in Example 13. MS (ES+): 496 (M+H). Calc'd. for C28H29N7O2—495.58.

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-{4-[2-Amino-3-(4-fluorophenyl)-propionyl]-3-ethyl-piperazin-1-yl}-N-methyl-3-naphthalen-2-yl-propioamide, 41, (0.78 g, 0.83 mmol) and Boc-L-azetidine-2-carboxylic acid (0.17 g, 0.83 mmol), 1-(3-dimethylamino-propyl)-3-ethylcarbodiimide (0.19 g, 1.0 mmol) and 1-hydroxybenzotriazole (0.22 g, 1.66 mmol) are dissolved in anhydrous DMF (2 mL). The reaction mixture is cooled to 0° C., then N-methylmorpholine (0.6 mL, 5.46 mmol) is added. The reaction mixture is stirred for 4 hrs. EtOAc (30 mL) and water (100 mL) are added, and the organic layer is separated. The aqueous layer is extracted with EtOAc (3×30 mL). All organic layers are combined and washed with water (2×50 mL), and dried over Na2SO4. The solution is concentrated in vacuo to afford the desired product which is used without further purification. the organic layer is separated The aqueous layer is extracted with EtOAc (3×30 mL) washed with water (2×50 mL) dried over Na2SO4 The solution is concentrated in vacuo

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

Procedure: 2.00 g 1-Tert.butoxycarbonyl-azetidin-2(S)-carboxylic acid, 1.70 g 1-amino-6-aminomethyl-isoquinolin, 3.50 g TBTU were dissolved in 40 mL DMF. 3.55 mL N-methylmorpholin was added slowly with stirring. The solution was applied to a reversed-phase chromatography column (lenght 100 mm, diameter 14 mm; Merck Lichroprep RP-18, 15-25 u). Elution was started with 25 mL of methanol/water containing 0.3% acetic acid (10 : 90), then a linear gradient to pure methanol over a period of 75 mL was applied followed by 50 mL of pure methanol. Fraktions of 5 mL each were sampled. The solvent was evaporated to give 3.4 g of the tile compound. MS: 357 Elution a linear gradient to pure methanol over a period of 75 mL was applied followed by 50 mL of pure methanol Fraktions of 5 mL each were sampled The solvent was evaporated

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

Procedure: To an ice-cooled solution of the compound of step 7a (9.39 g, 46.72 mmol) in tetrahydrofuran (100 mL) was added borane/THF complex (1 M, 210 mL, 4.5 eq.) under nitrogen. The reaction was gradually warmed to room temperature and stirred for 48 hours, after which a 10% aqueous potassium hydrogen sulfate solution (60 mL) was added gradually, then the volatiles were evaporated in vacuo. The remaining slurry was diluted with ethyl acetate (100 mL), and triturated two additional times. The organic phase was then washed with a saturated solution of sodium hydrogen carbonate (3×75 mL), dried (MgSO4), filtered and concentrated in vacuo, yielding a colorless oil (8.4 g, 96% yield). This material was carried forward without further purification. MS (DCI/NH3) m/e 188 (M+H)+. 1H NMR (CDCl3, 300 MHz) δ: 4.49-4.40 (ddd, J=9.0 Hz, J=9.0 Hz, J=3.0 Hz, 1H), 3.95-3.68 (m, 4H), 2.23-2.12 (m, 1H), 1.99-1.87 (m, 1H), 1.46 (s, 9H). was added borane/THF complex (1 M, 210 mL, 4.5 eq.) under nitrogen the volatiles were evaporated in vacuo The remaining slurry was diluted with ethyl acetate (100 mL) triturated two additional times The organic phase was then washed with a saturated solution of sodium hydrogen carbonate (3×75 mL) dried (MgSO4) filtered concentrated in vacuo