1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → Methyl 4-(4-(4-aminophenyl)-1-methyl-1H-pyrrole-2-carboxamido)-1-methyl-1H-pyrrole-2-carboxylate

Participants

Reaction Steps

Two eq of EDCI and 2.5 eq of DMAP were added to a stirred solution of 6 (0.45 gm, 1.2 eq) in DMF (8 mL) and the mixture was allowed to stir for 30 minutes after which commercially available methyl 4-amino-1-methyl-1H-pyrrole-2-carboxylate (0.18 g, 1.18 mmol, 1.0 eq) was added. The reaction mixture was allowed to stir for a further 6 hour at which point TLC showed completion of reaction. The reaction was quenched by pouring it onto a mixture of ice/water mixture and the resulting mixture was extracted with ethyl acetate (3×150 mL). The combined extracts were sequentially washed with citric acid (100 mL), saturated aqueous NaHCO3 (100 mL), water (100 mL), brine (100 mL) and finally dried over MgSO4. Excess ethyl acetate was evaporated by rotary evaporator under reduced pressure and the crude product 9a (0.58 gm, yield 90.6%) was used for the boc deprotection step to afford 9 without further purification. For boc deprotection, 0.29 gm of 9a was dissolved in a small volume of MeOH and 4M HCl in dioxane (15 mL) was added slowly to the stirring solution. The reaction mixture was stirred for 6 hours at which point TLC showed completion of reaction. Excess solvent was evaporated under vacuum to obtain a brown coloured solid (9). The solid product was subjected to flash chromatography (n-hexane/EtOAc 9:1) to give pure 9. Yield 0.21 gm, 95%.

Provenance & Evidence