title: Synthesis of New Functionalized Indoles Based on Ethyl Indol-2-carboxylate.
abstract: Successful alkylations of the nitrogen of ethyl indol-2-carboxylate were carried out using aq. KOH in acetone. The respective N-alkylated acids could be obtained without separating the N-alkylated esters by increasing the amount of KOH and water. The use of NaOMe in methanol led to transesterification instead of the alkylation, while the use of NaOEt led to low yields of the N-alkylated acids. Hydrazinolysis of the ester gave indol-2-carbohydrazide which then was allowed to react with different aromatic aldehydes and ketones in ethanol catalyzed by acetic acid. Indol-2-thiosemicarbazide was used in a heterocyclization reaction to form thiazoles. The new structures were confirmed using NMR, mass spectrometry and X-ray single crystal analysis.
authors.affiliation: Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522, Egypt. ahmed_tawfeek83@yahoo.com.
authors.forename: Ahmed T A
authors.initials: AT
authors.lastname: Boraei
authors.affiliation: Chemistry Department, Faculty of Science, Alexandria University, P. O. Box 426, Ibrahimia, Alexandria 21321, Egypt. eelashry60@hotmail.com.
authors.forename: El Sayed H
authors.initials: el SH
authors.lastname: El Ashry
authors.affiliation: Chemistry Department, College of Science, King Saud University, P. O. BOX 2455, Riyadh 11451, Saudi Arabia. ambarakat@ksu.edu.sa.|Chemistry Department, Faculty of Science, Alexandria University, P. O. Box 426, Ibrahimia, Alexandria 21321, Egypt. ambarakat@ksu.edu.sa.
authors.forename: Assem
authors.initials: A
authors.lastname: Barakat
authors.affiliation: Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P. O. Box 2457, Riyadh 11451, Saudi Arabia. ghabbourh@yahoo.com.|Department of Medicinal Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt. ghabbourh@yahoo.com.
authors.forename: Hazem A
authors.initials: HA
authors.lastname: Ghabbour
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D000478:Alkylation; D002264:Carboxylic Acids / Q000737:chemistry*; D004952:Esters / Q000737:chemistry; D006868:Hydrolysis; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D007659:Ketones / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D014961:X-Ray Diffraction
chemical_list: D000447:Aldehydes; D002264:Carboxylic Acids; D004952:Esters; D007211:Indoles; D007659:Ketones
keywords: alkylation; ethyl indol-2-carboxylate; hydrazinolysis; single-crystal X-ray diffraction