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See Example 26 for experimental details. Preparation of (S)-benzyl 2-(2-chloro-2-oxoethyl)pyrrolidine-1-carboxylate (143): i) Formation of (S)-2-(1-(benzyloxycarbonyl)pyrrolidin-2-yl)acetic acid: To a reaction vial fitted with a magnetic stirbar was added L-B-Homoproline hydrochloride (250 mg, 1.51 mmol) as an off-white solid. The vessel was closed with a septum and cap, and placed in an ice-water bath. 2 N Sodium hydroxide solution (1.45 mL) was added, and the salt dissolved to give a brown solution. The septum was pierced with 2 syringes, one containg benzyl chloroformate (280 μL, 1.96 mmol), the second with 1.1 mL of 2 N sodium hydroxide (2.20 mmol). A 3rd needle was added to relieve pressure. The two liquids were added alternatively, a little at a time to attempt to maintain a constant pH. After all reagents were added, the reaction was allowed to stir for 2 hours in the icewater bath. The reaction was transferred to a separatory funnel and ether (5 mL) was added. The ether layer was removed, and the aqueous acidified to a pH of 3 by the addition of 1 M aqueous HCl. The aqueous was extracted with ethyl acetate (3×5 mL). The combined organis were washed with brine, dried over sodium sulfate, decanted and concentrated to afford a yellow oil. Yield: 264 mg (66%) 1H NMR (DMSO-d6) δ 12.22 (bs, 1H), 7.35 (m, 5H), 5.07 (s, 2H), 4.05-4.02 (t, J=7.2 Hz, 2H), 3.32-2.63 (m, 1H), 2.31-2.28 (m, 1H), 1.99 (s, 2H), 1.90-1.68 (m, 4H), 1.20-1.15 (t, J=7.2 Hz, 1H). ii) To an argon purged round bottom flask fitted with a magnetic stirbar was added (S)-2-(1-(benzyloxycarbonyl)pyrrolidin-2-yl)acetic acid (235 mg, 0.893 mmol) followed by anhydrous dichloromethane (5 mL). The reaction was treated with anhydrous DMF (2 drops ˜5 μL). The flow of argon was stopped, and the reaction vessel fitted with a balloon. Oxalyl chloride (0.12 mL, 1.38 mmol) was added in two portions, resulting in effervescence. The reaction was stirred at room temperature for 3 hours, before being concentrated to dryness under reduced pressure and dried overnight under high vacuum. Preparation of (S)-benzyl 2-(2-(5-(2,5-dimethyl-1H-pyrrol-1-yl)-1H-indol-3-yl)-2-oxoethyl)pyrrolidine-1-carboxylate (144): In a similar fashion to the synthesis of compound 94, Example 26, compound 144 was isolated as a yellow solid (240 mg, 59%).

1. customvial fitted with a magnetic stirbar
2. customThe vessel was closed with a septum
3. customcap
4. customplaced in an ice-water bath
5. dissolutionthe salt dissolved
6. customto give a brown solution
7. additionA 3rd needle was added
8. additionThe two liquids were added alternatively
9. temperatureto maintain a constant pH
10. additionAfter all reagents were added
11. customThe reaction was transferred to a separatory funnel
12. customThe ether layer was removed
13. additionthe aqueous acidified to a pH of 3 by the addition of 1 M aqueous HCl
14. extractionThe aqueous was extracted with ethyl acetate (3×5 mL)
15. washThe combined organis were washed with brine
16. dry with materialdried over sodium sulfate
17. customdecanted
18. concentrationconcentrated
19. customto afford a yellow oil
20. customthe reaction vessel fitted with a balloon
21. customresulting in effervescence
22. stirringThe reaction was stirred at room temperature for 3 hours
23. concentrationbefore being concentrated to dryness under reduced pressure
24. customdried overnight under high vacuum
25. customPreparation of (S)-benzyl 2-(2-(5-(2,5-dimethyl-1H-pyrrol-1-yl)-1H-indol-3-yl)-2-oxoethyl)pyrrolidine-1-carboxylate (144)