ethyl 2-[(4-fluorophenyl)methylamino]cyclopentane-1-carboxylate

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

Conditions: temp:23.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Sodium triacetoxyborohydride (62.1 g, 293 mmol) was suspended in a 1:1 mixture of glacial acetic acid and acetonitrile (200 mL) at 0° C. The crude 2-(4-fluoro-benzylamino)-cyclopent-1-enecarboxylic acid ethyl ester was added via cannula over 15 min and the resulting orange/brown suspension was allowed to warm to 23° C. over 19 h. A 4.0 M aqueous hydrochloric acid solution (60 mL) was then carefully added and the mixture was stirred at 23° C. for 20 min. The mixture was transferred to a large Erlenmeyer flask containing a stir bar and was cooled to 0° C. Aqueous sodium hydroxide (98 g dissolved in 350 mL; approx. 8.0 M) was then added over 20 min with gentle stirring and continued external cooling (large exotherm noted; melted ice was replenished). After the exotherm subsided, the mixture was transferred to a separatory funnel and the phases were separated. The aqueous phase was extracted with ethyl acetate (1×300 mL) and the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL), dried over sodium sulfate, filtered and were concentrated in vacuo. Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes) afforded the desired product, cis-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (19.9 g, 77% over two steps), as a pale yellow oil. 1H NMR (CDCl3) δ: 1.27 (3H, t, J=7.0), 1.55-1.71 (2H, m), 1.81-1.91 (4H, m), 1.98-2.06 (1H, m), 2.90-2.96 (1H, m), 3.26-3.31 (1H, m), 3.73 (1H, d, J=13.1), 3.77 (1H, d, J=13.2), 4.15 (2H, q, J=7.3), 6.94-7.00 (2H, m), 7.24-7.28 (2H, m). 13C NMR (CDCl3) δ: 14.8, 22.7, 27.9, 32.2, 48.0, 51.9, 60.5, 61.7, 115.2 (d, J=21.5), 129.6 (d, J=8.4), 136.5 (d, J=3.1), 161.9 (d, J=243.8), 174.7. Anal. calculated for C15H20FNO2: C, 67.90; H, 7.60; N, 5.28. found: C, 67.92; H, 7.88; N, 5.55. Continued elution of the silica gel column with increasing amounts of ethyl acetate (up to 100% of eluent concentration) afforded trans-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (3.2 g, 12%) as a dark orange oil. 1H NMR (CDCl3) δ: 1.26 (3H, t, J=7.0), 1.40-1.49 (1H, m), 1.67-1.77 (2H, m), 1.82-1.91 (1H, m), 1.97-2.05 (2H, m), 2.58 (1H, q, J=7.9), 3.31 (1H, q, J=7.3), 3.72 (1H, d, J=13.2), 3.77 (1H, d, J=12.5), 4.14 (2H, q, J=7.0), 6.96-7.01 (2H, m), 7.24-7.29 (2H, m). The mixture was transferred to a large Erlenmeyer flask containing a stir bar was cooled to 0° C with gentle stirring continued external cooling (large exotherm noted; melted ice was replenished) the mixture was transferred to a separatory funnel the phases were separated The aqueous phase was extracted with ethyl acetate (1×300 mL) the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL) dried over sodium sulfate filtered were concentrated in vacuo Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes)

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-(4-Fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (prepared as described in Example 11, 133.5 mg, 0.503 mmol) was mixed with (1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-3-yl)-acetic acid (132.9 mg, 0.554 mmol) in N,N-dimethylformamide (4.6 mL). N-methylmorpholine (122 μL, 1.11 mmol) was added followed by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (106.2 mg, 0.554 mmol). The reaction mixture was shaken at 25° C. for 16 h. A 1.0 M aqueous hydrochloric acid solution (4.6 mL) was added at 25° C., and the aqueous layer was extracted with ethyl acetate (3×15 mL). The combined organic layers were washed with saturated aqueous brine solution (10 mL). The organic layer was dried over sodium sulfate, filtered, concentrated and dried in vacuo to afford the crude product, 2-[[2-(1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-3-yl)-acetyl]-(4-fluoro-benzyl)-amino]-cyclopentanecarboxylic acid ethyl ester, as a pale yellow oil, which was directly used in the next step without further purification. LC-MS (ESI) calcd for C24H26FN3O5S 487.16, found 488.3 [M+H+]. the aqueous layer was extracted with ethyl acetate (3×15 mL) The combined organic layers were washed with saturated aqueous brine solution (10 mL) The organic layer was dried over sodium sulfate filtered concentrated dried in vacuo

Conditions: temp:23.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Sodium triacetoxyborohydride (62.1 g, 293 mmol) was suspended in a 1:1 mixture of glacial acetic acid and actonitrile (200 mL) at 0° C. The crude 2-(4-fluoro-benzylamino)-cyclopent-1-enecarboxylic acid ethyl ester was added via cannula over 15 min and the resulting orange/brown suspension was allowed to warm to 23° C. over 19 h. A 4.0 M aqueous hydrochloric acid solution (60 mL) was then carefully added and the mixture was stirred at 23° C. for 20 min. The mixture was transferred to a large Erlenmeyer flask containing a stirbar and was cooled to 0° C. Aqueous sodium hydroxide (98 g dissolved in 350 mL; approx. 8.0 M) was then added over 20 min with gentle stirring and continued external cooling (large exotherm noted; melted ice was replenished). After the exotherm subsided, the mixture was transferred to a separatory funnel and the phases were separated. The aqueous phase was extracted with ethyl acetate (1×300 mL) and the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL), dried over sodium sulfate, filtered and were concentrated in vacuo. Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes) afforded the desired product, cis-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (19.9 g, 77% over two steps), as a pale yellow oil. 1H NMR (CDCl3) δ: 1.27 (3H, t, J=7.0), 1.55-1.71 (2H, m), 1.81-1.91 (4H, m), 1.98-2.06 (1H, m), 2.90-2.96 (1H, m), 3.26-3.31 (1H, m), 3.73 (1H, d, J=13.1), 3.77 (1H, d, J=13.2), 4.15 (2H, q, J=7.3), 6.94-7.00 (2H, m), 7.24-7.28 (2H, m). 13C NMR (CDCl3) δ: 14.8, 22.7, 27.9, 32.2, 48.0, 51.9, 60.5, 61.7, 115.2 (d, J=21.5), 129.6 (d, J=8.4), 136.5 (d, J=3.1), 161.9 (d, J=243.8), 174.7. Anal. calcd for C15H20FNO2: C, 67.90; H, 7.60; N, 5.28; Found: C, 67.92; H, 7.88; N, 5.55. Continued elution of the silica gel column with increasing amounts of ethyl acetate (up to 100% of eluent concentration) afforded trans-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (3.2 g, 12%) as a dark orange oil. 1H NMR (CDCl3) δ: 1.26 (3H, t, J=7.0), 1.40-1.49 (1H, m), 1.67-1.77 (2H, m), 1.82-1.91 (1H, m), 1.97-2.05 (2H, m), 2.58 (1H, q, J=7.9), 3.31 (1H, q, J=7.3), 3.72 (1H, d, J=13.2), 3.77 (1H, d, J=12.5), 4.14 (2H, q, J=7.0), 6.96-7.01 (2H, m), 7.24-7.29 (2H, m). The mixture was transferred to a large Erlenmeyer flask containing a stirbar was cooled to 0° C with gentle stirring continued external cooling (large exotherm noted; melted ice was replenished) the mixture was transferred to a separatory funnel the phases were separated The aqueous phase was extracted with ethyl acetate (1×300 mL) the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL) dried over sodium sulfate filtered were concentrated in vacuo Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes)

Conditions: temp:23.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Sodium triacetoxyborohydride (62.1 g, 293 mmol) was suspended in a 1:1 mixture of glacial acetic acid and actonitrile (200 mL) at 0° C. The crude 2-(4-fluoro-benzylamino)-cyclopent-1-enecarboxylic acid ethyl ester was added via cannula over 15 min and the resulting orange/brown suspension was allowed to warm to 23° C. over 19 h. A 4.0 M aqueous hydrochloric acid solution (60 mL) was then carefully added and the mixture was stirred at 23° C. for 20 min. The mixture was transferred to a large Erlenmeyer flask containing a stirbar and was cooled to 0° C. Aqueous sodium hydroxide (98 g dissolved in 350 mL; approx. 8.0 M) was then added over 20 min with gentle stirring and continued external cooling (large exotherm noted; melted ice was replenished). After the exotherm subsided, the mixture was transferred to a separatory funnel and the phases were separated. The aqueous phase was extracted with ethyl acetate (1×300 mL) and the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL), dried over sodium sulfate, filtered and were concentrated in vacuo. Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes) afforded the desired product, cis-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (19.9 g, 77% over two steps), as a pale yellow oil. 1H NMR (CDCl3) δ: 1.27 (3H, t, J=7.0), 1.55-1.71 (2H, m), 1.81-1.91 (4H, m), 1.98-2.06 (1H, m), 2.90-2.96 (1H, m), 3.26-3.31 (1H, m), 3.73 (1H, d, J=13.1), 3.77 (1H, d, J=13.2), 4.15 (2H, q, J=7.3), 6.94-7.00 (2H, m), 7.24-7.28 (2H, m). 13C NMR (CDCl3) δ: 14.8, 22.7, 27.9, 32.2, 48.0, 51.9, 60.5, 61.7, 115.2 (d, J=21.5), 129.6 (d, J=8.4), 136.5 (d, J=3.1), 161.9 (d, J=243.8), 174.7. Anal. calcd for C15H20FNO2: C, 67.90; H, 7.60; N, 5.28; Found: C, 67.92; H, 7.88; N, 5.55. Continued elution of the silica gel column with increasing amounts of ethyl acetate (up to 100% of eluent concentration) afforded trans-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (3.2 g, 12%) as a dark orange oil. 1H NMR (CDCl3) δ: 1.26 (3H, t, J=7.0), 1.40-1.49 (1H, m), 1.67-1.77 (2H, m), 1.82-1.91 (1H, m), 1.97-2.05 (2H, m), 2.58 (1H, q, J=7.9), 3.31 (1H, q, J=7.3), 3.72 (1H, d, J=13.2), 3.77 (1H, d, J=12.5), 4.14 (2H, q, J=7.0), 6.96-7.01 (2H, m), 7.24-7.29 (2H, m). The mixture was transferred to a large Erlenmeyer flask containing a stirbar was cooled to 0° C with gentle stirring continued external cooling (large exotherm noted; melted ice was replenished) the mixture was transferred to a separatory funnel the phases were separated The aqueous phase was extracted with ethyl acetate (1×300 mL) the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL) dried over sodium sulfate filtered were concentrated in vacuo Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes)

Conditions: temp:23.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Sodium triacetoxyborohydride (62.1 g, 293 mmol) was suspended in a 1:1 mixture of glacial acetic acid and acetonitrile (200 mL) at 0° C. The crude 2-(4-fluoro-benzylamino)-cyclopent-1-enecarboxylic acid ethyl ester was added via cannula over 15 min and the resulting orange/brown suspension was allowed to warm to 23° C. over 19 h. A 4.0 M aqueous hydrochloric acid solution (60 mL) was then carefully added and the mixture was stirred at 23° C. for 20 min. The mixture was transferred to a large Erlenmeyer flask containing a stir bar and was cooled to 0° C. Aqueous sodium hydroxide (98 g dissolved in 350 mL; approx. 8.0 M) was then added over 20 min with gentle stirring and continued external cooling (large exotherm noted; melted ice was replenished). After the exotherm subsided, the mixture was transferred to a separatory funnel and the phases were separated. The aqueous phase was extracted with ethyl acetate (1×300 mL) and the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL), dried over sodium sulfate, filtered and were concentrated in vacuo. Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes) afforded the desired product, cis-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (19.9 g, 77% over two steps), as a pale yellow oil. 1H NMR (CDCl3) δ: 1.27 (3H, t, J=7.0), 1.55-1.71 (2H, m), 1.81-1.91 (4H, m), 1.98-2.06 (1H, m), 2.90-2.96 (1H, m), 3.26-3.31 (1H, m), 3.73 (1H, d, J=13.1), 3.77 (1H, d, J=13.2), 4.15 (2H, q, J=7.3), 6.94-7.00 (2H, m), 7.24-7.28 (2H, m). 13C NMR (CDCl3) δ: 14.8, 22.7, 27.9, 32.2, 48.0, 51.9, 60.5, 61.7, 115.2 (d, J=21.5), 129.6 (d, J=8.4), 136.5 (d, J=3.1), 161.9 (d, J=243.8), 174.7. Anal. calculated for C15H20FNO2: C, 67.90; H, 7.60; N, 5.28. found: C, 67.92; H, 7.88; N, 5.55. Continued elution of the silica gel column with increasing amounts of ethyl acetate (up to 100% of eluent concentration) afforded trans-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (3.2 g, 12%) as a dark orange oil. 1H NMR (CDCl3) δ: 1.26 (3H, t, J=7.0), 1.40-1.49 (1H, m), 1.67-1.77 (2H, m), 1.82-1.91 (1H, m), 1.97-2.05 (2H, m), 2.58 (1H, q, J=7.9), 3.31 (1H, q, J=7.3), 3.72 (1H, d, J=13.2), 3.77 (1H, d, J=12.5), 4.14 (2H, q, J=7.0), 6.96-7.01 (2H, m), 7.24-7.29 (2H, m). The mixture was transferred to a large Erlenmeyer flask containing a stir bar was cooled to 0° C with gentle stirring continued external cooling (large exotherm noted; melted ice was replenished) the mixture was transferred to a separatory funnel the phases were separated The aqueous phase was extracted with ethyl acetate (1×300 mL) the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL) dried over sodium sulfate filtered were concentrated in vacuo Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes)

Conditions: temp:23.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Sodium triacetoxyborohydride (62.1 g, 293 mmol) was suspended in a 1:1 mixture of glacial acetic acid and acetonitrile (200 mL) at 0° C. The crude 2-(4-fluoro-benzylamino)-cyclopent-1-enecarboxylic acid ethyl ester was added via cannula over 15 min and the resulting orange/brown suspension was allowed to warm to 23° C. over 19 h. A 4.0 M aqueous hydrochloric acid solution (60 mL) was then carefully added and the mixture was stirred at 23° C. for 20 min. The mixture was transferred to a large Erlenmeyer flask containing a stir bar and was cooled to 0° C. Aqueous sodium hydroxide (98 g dissolved in 350 mL; approx. 8.0 M) was then added over 20 min with gentle stirring and continued external cooling (large exotherm noted; melted ice was replenished). After the exotherm subsided, the mixture was transferred to a separatory funnel and the phases were separated. The aqueous phase was extracted with ethyl acetate (1×300 mL) and the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL), dried over sodium sulfate, filtered and were concentrated in vacuo. Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes) afforded the desired product, cis-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (19.9 g, 77% over two steps), as a pale yellow oil. 1H NMR (CDCl3) δ: 1.27 (3H, t, J=7.0), 1.55-1.71 (2H, m), 1.81-1.91 (4H, m), 1.98-2.06 (1H, m), 2.90-2.96 (1H, m), 3.26-3.31 (1H, m), 3.73 (1H, d, J=13.1), 3.77 (1H, d, J=13.2), 4.15 (2H, q, J=7.3), 6.94-7.00 (2H, m), 7.24-7.28 (2H, m). 13C NMR (CDCl3) δ: 14.8, 22.7, 27.9, 32.2, 48.0, 51.9, 60.5, 61.7, 115.2 (d, J=21.5), 129.6 (d, J=8.4), 136.5 (d, J=3.1), 161.9 (d, J=243.8), 174.7. Anal. calculated for C15H20FNO2: C, 67.90; H, 7.60; N, 5.28. found: C, 67.92; H, 7.88; N, 5.55. Continued elution of the silica gel column with increasing amounts of ethyl acetate (up to 100% of eluent concentration) afforded trans-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (3.2 g, 12%) as a dark orange oil. 1H NMR (CDCl3) δ: 1.26 (3H, t, J=7.0), 1.40-1.49 (1H, m), 1.67-1.77 (2H, m), 1.82-1.91 (1H, m), 1.97-2.05 (2H, m), 2.58 (1H, q, J=7.9), 3.31 (1H, q, J=7.3), 3.72 (1H, d, J=13.2), 3.77 (1H, d, J=12.5), 4.14 (2H, q, J=7.0), 6.96-7.01 (2H, m), 7.24-7.29 (2H, m). The mixture was transferred to a large Erlenmeyer flask containing a stir bar was cooled to 0° C with gentle stirring continued external cooling (large exotherm noted; melted ice was replenished) the mixture was transferred to a separatory funnel the phases were separated The aqueous phase was extracted with ethyl acetate (1×300 mL) the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL) dried over sodium sulfate filtered were concentrated in vacuo Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes)

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

Conditions: temp:23.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Sodium triacetoxyborohydride (62.1 g, 293 mmol) was suspended in a 1:1 mixture of glacial acetic acid and actonitrile (200 mL) at 0° C. The crude 2-(4-fluoro-benzylamino)-cyclopent-1-enecarboxylic acid ethyl ester was added via cannula over 15 min and the resulting orange/brown suspension was allowed to warm to 23° C. over 19 h. A 4.0 M aqueous hydrochloric acid solution (60 mL) was then carefully added and the mixture was stirred at 23° C. for 20 min. The mixture was transferred to a large Erlenmeyer flask containing a stirbar and was cooled to 0° C. Aqueous sodium hydroxide (98 g dissolved in 350 mL; approx. 8.0 M) was then added over 20 min with gentle stirring and continued external cooling (large exotherm noted; melted ice was replenished). After the exotherm subsided, the mixture was transferred to a separatory funnel and the phases were separated. The aqueous phase was extracted with ethyl acetate (1×300 mL) and the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL), dried over sodium sulfate, filtered and were concentrated in vacuo. Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes) afforded the desired product, cis-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (19.9 g, 77% over two steps), as a pale yellow oil. 1H NMR (CDCl3) δ: 1.27 (3H, t, J=7.0), 1.55-1.71 (2H, m), 1.81-1.91 (4H, m), 1.98-2.06 (1H, m), 2.90-2.96 (1H, m), 3.26-3.31 (1H, m), 3.73 (1H, d, J=13.1), 3.77 (1H, d, J=13.2), 4.15 (2H, q, J=7.3), 6.94-7.00 (2H, m), 7.24-7.28 (2H, m). 13C NMR (CDCl3) δ: 14.8, 22.7, 27.9, 32.2, 48.0, 51.9, 60.5, 61.7, 115.2 (d, J=21.5), 129.6 (d, J=8.4), 136.5 (d, J=3.1), 161.9 (d, J=243.8), 174.7. Anal. calcd for C15H20FNO2: C, 67.90; H, 7.60; N, 5.28; Found: C, 67.92; H, 7.88; N, 5.55. Continued elution of the silica gel column with increasing amounts of ethyl acetate (up to 100% of eluent concentration) afforded trans-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (3.2 g, 12%) as a dark orange oil. 1H NMR (CDCl3) δ: 1.26 (3H, t, J=7.0), 1.40-1.49 (1H, m), 1.67-1.77 (2H, m), 1.82-1.91 (1H, m), 1.97-2.05 (2H, m), 2.58 (1H, q, J=7.9), 3.31 (1H, q, J=7.3), 3.72 (1H, d, J=13.2), 3.77 (1H, d, J=12.5), 4.14 (2H, q, J=7.0), 6.96-7.01 (2H, m), 7.24-7.29 (2H, m). The mixture was transferred to a large Erlenmeyer flask containing a stirbar was cooled to 0° C with gentle stirring continued external cooling (large exotherm noted; melted ice was replenished) the mixture was transferred to a separatory funnel the phases were separated The aqueous phase was extracted with ethyl acetate (1×300 mL) the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL) dried over sodium sulfate filtered were concentrated in vacuo Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes)

Conditions: temp:23.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Sodium triacetoxyborohydride (62.1 g, 293 mmol) was suspended in a 1:1 mixture of glacial acetic acid and acetonitrile (200 mL) at 0° C. The crude 2-(4-fluoro-benzylamino)-cyclopent-1-enecarboxylic acid ethyl ester was added via cannula over 15 min and the resulting orange/brown suspension was allowed to warm to 23° C. over 19 h. A 4.0 M aqueous hydrochloric acid solution (60 mL) was then carefully added and the mixture was stirred at 23° C. for 20 min. The mixture was transferred to a large Erlenmeyer flask containing a stir bar and was cooled to 0° C. Aqueous sodium hydroxide (98 g dissolved in 350 mL; approx. 8.0 M) was then added over 20 min with gentle stirring and continued external cooling (large exotherm noted; melted ice was replenished). After the exotherm subsided, the mixture was transferred to a separatory funnel and the phases were separated. The aqueous phase was extracted with ethyl acetate (1×300 mL) and the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL), dried over sodium sulfate, filtered and were concentrated in vacuo. Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes) afforded the desired product, cis-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (19.9 g, 77% over two steps), as a pale yellow oil. 1H NMR (CDCl3) δ: 1.27 (3H, t, J=7.0), 1.55-1.71 (2H, m), 1.81-1.91 (4H, m), 1.98-2.06 (1H, m), 2.90-2.96 (1H, m), 3.26-3.31 (1H, m), 3.73 (1H, d, J=13.1), 3.77 (1H, d, J=13.2), 4.15 (2H, q, J=7.3), 6.94-7.00 (2H, m), 7.24-7.28 (2H, m). 13C NMR (CDCl3) δ: 14.8, 22.7, 27.9, 32.2, 48.0, 51.9, 60.5, 61.7, 115.2 (d, J=21.5), 129.6 (d, J=8.4), 136.5 (d, J=3.1), 161.9 (d, J=243.8), 174.7. Anal. calculated for C15H20FNO2, C, 67.90; H, 7.60; N, 5.28. found: C, 67.92; H, 7.88; N, 5.55. Continued elution of the silica gel column with increasing amounts of ethyl acetate (up to 100% of eluent concentration) afforded trans-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (3.2 g, 12%) as a dark orange oil. 1H NMR (CDCl3) δ: 1.26 (3H, t, J=7.0), 1.40-1.49 (1H, m), 1.67-1.77 (2H, m), 1.82-1.91 (1H, m), 1.97-2.05 (2H, m), 2.58 (1H, q, J=7.9), 3.31 (1H, q, J=7.3), 3.72 (1H, d, J=13.2), 3.77 (1H, d, J=12.5), 4.14 (2H, q, J=7.0), 6.96-7.01 (2H, m), 7.24-7.29 (2H, m). The mixture was transferred to a large Erlenmeyer flask containing a stir bar was cooled to 0° C with gentle stirring continued external cooling (large exotherm noted; melted ice was replenished) the mixture was transferred to a separatory funnel the phases were separated The aqueous phase was extracted with ethyl acetate (1×300 mL) the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL) dried over sodium sulfate filtered were concentrated in vacuo Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes)

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-(4-Fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (prepared as described in Example 11, 133.5 mg, 0.503 mmol) was mixed with (1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-3-yl)-acetic acid (132.9 mg, 0.554 mmol) in N,N-dimethylformamide (4.6 mL). N-methylmorpholine (122 μL, 1.11 mmol) was added followed by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (106.2 mg, 0.554 mmol). The reaction mixture was shaken at 25° C. for 16 h. A 1.0 M aqueous hydrochloric acid solution (4.6 mL) was added at 25° C., and the aqueous layer was extracted with ethyl acetate (3×15 mL). The combined organic layers were washed with saturated aqueous brine solution (10 mL). The organic layer was dried over sodium sulfate, filtered, concentrated and dried in vacuo to afford the crude product, 2-[[2-(1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-3-yl)-acetyl]-(4-fluoro-benzyl)-amino]-cyclopentanecarboxylic acid ethyl ester, as a pale yellow oil, which was directly used in the next step without further purification. LC-MS (ESI) calcd for C24H26FN3O5S 487.16, found 488.3 [M+H+]. the aqueous layer was extracted with ethyl acetate (3×15 mL) The combined organic layers were washed with saturated aqueous brine solution (10 mL) The organic layer was dried over sodium sulfate filtered concentrated dried in vacuo

Conditions: temp:23.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Sodium triacetoxyborohydride (62.1 g, 293 mmol) was suspended in a 1:1 mixture of glacial acetic acid and acetonitrile (200 mL) at 0° C. The crude 2-(4-fluoro-benzylamino)-cyclopent-1-enecarboxylic acid ethyl ester was added via cannula over 15 min and the resulting orange/brown suspension was allowed to warm to 23° C. over 19 h. A 4.0 M aqueous hydrochloric acid solution (60 mL) was then carefully added and the mixture was stirred at 23° C. for 20 min. The mixture was transferred to a large Erlenmeyer flask containing a stir bar and was cooled to 0° C. Aqueous sodium hydroxide (98 g dissolved in 350 mL; approx. 8.0 M) was then added over 20 min with gentle stirring and continued external cooling (large exotherm noted; melted ice was replenished). After the exotherm subsided, the mixture was transferred to a separatory funnel and the phases were separated. The aqueous phase was extracted with ethyl acetate (1×300 mL) and the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL), dried over sodium sulfate, filtered and were concentrated in vacuo. Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes) afforded the desired product, cis-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (19.9 g, 77% over two steps), as a pale yellow oil. 1H NMR (CDCl3) δ: 1.27 (3H, t, J=7.0), 1.55-1.71 (2H, m), 1.81-1.91 (4H, m), 1.98-2.06 (1H, m), 2.90-2.96 (1H, m), 3.26-3.31 (1H, m), 3.73 (1H, d, J=13.1), 3.77 (1H, d, J=13.2), 4.15 (2H, q, J=7.3), 6.94-7.00 (2H, m), 7.24-7.28 (2H, m). 13C NMR (CDCl3) δ: 14.8, 22.7, 27.9, 32.2, 48.0, 51.9, 60.5, 61.7, 115.2 (d, J=21.5), 129.6 (d, J=8.4), 136.5 (d, J=3.1), 161.9 (d, J=243.8), 174.7. Anal. calculated for C15H20FNO2: C, 67.90; H, 7.60; N, 5.28. found: C, 67.92; H, 7.88; N, 5.55. Continued elution of the silica gel column with increasing amounts of ethyl acetate (up to 100% of eluent concentration) afforded trans-2-(4-fluoro-benzylamino)-cyclopentanecarboxylic acid ethyl ester (3.2 g, 12%) as a dark orange oil. 1H NMR (CDCl3) δ: 1.26 (3H, t, J=7.0), 1.40-1.49 (1H, m), 1.67-1.77 (2H, m), 1.82-1.91 (1H, m), 1.97-2.05 (2H, m), 2.58 (1H, q, J=7.9), 3.31 (1H, q, J=7.3), 3.72 (1H, d, J=13.2), 3.77 (1H, d, J=12.5), 4.14 (2H, q, J=7.0), 6.96-7.01 (2H, m), 7.24-7.29 (2H, m). The mixture was transferred to a large Erlenmeyer flask containing a stir bar was cooled to 0° C with gentle stirring continued external cooling (large exotherm noted; melted ice was replenished) the mixture was transferred to a separatory funnel the phases were separated The aqueous phase was extracted with ethyl acetate (1×300 mL) the combined organic layers were washed with half-saturated aqueous sodium bicarbonate solution (1×200 mL) dried over sodium sulfate filtered were concentrated in vacuo Purification of the residue by flash chromatography (Teledyne Isco RediSep Column; 15-40% ethyl acetate in hexanes)