Triethylamine → Methyl 4-{bis[(3-chloropropyl)sulfonyl]amino}-1-ethyl-1H-indole-6-carboxylate

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Reaction Steps

To a solution of methyl 4-amino-1-ethyl-1H-indole-6-carboxylate hydrochloride salt (D202) (1.7 g, 6.68 mmol, 1 equiv) in CH2Cl2 (50 ml) was added NEt3 (4.2 ml, 30 mmol, 4.5 equiv) then 3-chloro-1-propanesulfonyl chloride (1.8 ml, 15.0 mmol, 2.2 equiv) and the resulting mixture was stirred for 2 h. The organic phase was washed with a 2N aqueous HCl solution and a saturated aqueous NaHCO3 solution, dried over MgSO4 and concentrated in vacuo. Purification of the residue by flash chromatography on silica gel (AcOEt/iso-hexane: 1/1) gave methyl 4-{bis[(3-chloropropyl)sulfonyl]amino}-1-ethyl-1H-indole-6-carboxylate (D236) (1.85 g, 55%) as a light tan solid. [M−H]−=498.1, RT=3.51 min.

Provenance & Evidence