Ethyl chloroformate → ethyl pyrrole-1-carboxylate
Reaction equation
[N:1]12[CH2:9][CH2:8][CH2:7][C:6]1=NCCC2.Cl[C:11]([O:13][CH2:14][CH3:15])=[O:12]>ClCCl>[C:11]([N:1]1[CH:9]=[CH:8][CH:7]=[CH:6]1)([O:13][CH2:14][CH3:15])=[O:12]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 25 °C
Procedure
To a solution of compound ◯3 (10.43 g, 20 mmol.) in dichloromethane (100 ml) at 0° C. was added DBN (1,5-diazabicyclo[4,3,0]non-5-ene) (4.96 g, 40 mmol.) followed by a solution of ethyl chloroformate (3.42 g, 32 mmol.) in dichloromethane (20 ml). After completion of the transformation to the N-carboethoxy derivative 4 (approximately 1 hour), an additional equivalent of DBN (2.48 g, 20 mmol.) was added and the reaction mixture was stirred at 25° C. for 20 hours and evaporated to dryness. Chromatographic purification of the residue on silica gel (chloroform/ethyl acetate; 9/1) afforded the N-carboethoxy pyrrole ◯5 (α, β-anomeric mixture) as a white foam (10 g, 84% from ◯3 ). The structure was confirmed by CHN elemental analysis and NMR spectroscopy.
Workup
- customevaporated to dryness
- customChromatographic purification of the residue on silica gel (chloroform/ethyl acetate; 9/1)
Sources & evidence
- ORD record
- ord-645ae101232b467d8817d3d8fc7729eb
- Source dataset
- uspto-grants-1986_04
- Patent number
- US04584369
Reaction notes
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