3-(2-Ethoxycarbonylethyl)-2,4-dimethyl-5-formylpyrrole synthesis

Yield:-

Reaction Conditions:

in tetrahydrofuran; for 2 h;Reflux;

Steps:

Ethyl (5-formyl-2,4-dimethyl-1H-pyrrole)-3-carboxylate (7) and ethyl 3-(5-formyl-2,4-dimethyl-1H-pyrrol-3-yl)propanoate (8)

General procedure: Methyl chloroformate (0.101g, 1.076mmol) was added into a stirred solution of 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (5) or 3-(5-formyl-2,4-dimethyl-1H-pyrrol-3-yl)propanoic acid (6) (0.897mmol) and triethylamine (0.181g, 1.794mmol) in THF (10mL). Reaction mixture was stirred at room temperature for 4h, and then ethanol (0.2mL, 3.588mmol) was added. The resulting mixture was heated at reflux for 2h. The reaction mixture was cooled to room temperature and evaporated in vacuo. After evaporation, the residue was extracted with chloroform and washed first with 0.1N HCl, and then with saturated NaHCO₃ and brine. Organic extract was dried over anhydrous MgSO₄, filtered through Celite and evaporated to give the corresponding crude ethyl esters 7 [67] and 8[68], which were used for the aldol condensations without purification.

References:

Jagtap, Ajit Dhananjay;Chang, Pei-Teh;Liu, Jia-Rong;Wang, Hsiao-Chun;Kondekar, Nagendra B.;Shen, Li-Jiuan;Tseng, Hsiang-Wen;Chen, Grace Shiahuy;Chern, Ji-Wang [European Journal of Medicinal Chemistry,2014,vol. 85,p. 268 - 288]