title: Direct Aminolysis of Ethoxycarbonylmethyl 1,4-Dihydropyridine-3-carboxylates.
abstract: The ethoxycarbonylmethyl esters of 1,4-dihydropyridines were directly converted into carbamoylmethyl esters in the presence of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) in good to excellent yields under mild conditions. The use of TBD is crucial for the successful aminolysis of ethoxycarbonylmethyl ester of 1,4-dihydropyridines with secondary amines as without it the reaction does not proceed at all. The aminolysis reaction proceeded regioselectively, as the alkyl ester conjugated with the 1,4-dihydropyridine cycle was not involved in the reaction. Screening of other N-containing bases, such as triethylamine (TEA), pyridine, 4-(N,N-dimethylamino)pyridine (DMAP), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), imidazole, tetramethyl guanidine (TMG) and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) as catalysts revealed no activity in the studied reaction.
authors.affiliation: Latvian Institute of Organic Synthesis, Aizkraukles str. 21, Riga LV-1006, Latvia. vigante@osi.lv.
authors.forename: Brigita
authors.initials: B
authors.lastname: Vigante
authors.affiliation: Latvian Institute of Organic Synthesis, Aizkraukles str. 21, Riga LV-1006, Latvia. rucins@osi.lv.
authors.forename: Martins
authors.initials: M
authors.lastname: Rucins
authors.affiliation: Latvian Institute of Organic Synthesis, Aizkraukles str. 21, Riga LV-1006, Latvia. aiva@osi.lv.
authors.forename: Aiva
authors.initials: A
authors.lastname: Plotniece
authors.affiliation: Latvian Institute of Organic Synthesis, Aizkraukles str. 21, Riga LV-1006, Latvia. kpajuste@osi.lv.
authors.forename: Karlis
authors.initials: K
authors.lastname: Pajuste
authors.affiliation: Latvian Institute of Organic Synthesis, Aizkraukles str. 21, Riga LV-1006, Latvia. iveta.vesere@gmail.com.
authors.forename: Iveta
authors.initials: I
authors.lastname: Luntena
authors.affiliation: Latvian Institute of Organic Synthesis, Aizkraukles str. 21, Riga LV-1006, Latvia. brigita.cekavicus@inbox.lv.
authors.forename: Brigita
authors.initials: B
authors.lastname: Cekavicus
authors.affiliation: Latvian Institute of Organic Synthesis, Aizkraukles str. 21, Riga LV-1006, Latvia. egils.bisenieks@osi.lv.
authors.forename: Egils
authors.initials: E
authors.lastname: Bisenieks
authors.affiliation: Latvian Institute of Organic Synthesis, Aizkraukles str. 21, Riga LV-1006, Latvia. rufs@osi.lv.
authors.forename: Rufus
authors.initials: R
authors.lastname: Smits
authors.affiliation: Latvian Institute of Organic Synthesis, Aizkraukles str. 21, Riga LV-1006, Latvia. gduburs@osi.lv.
authors.forename: Gunars
authors.initials: G
authors.lastname: Duburs
authors.affiliation: Latvian Institute of Organic Synthesis, Aizkraukles str. 21, Riga LV-1006, Latvia. arkady@osi.lv.
authors.forename: Arkadij
authors.initials: A
authors.lastname: Sobolev
mesh_terms: D000588:Amines / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D004095:Dihydropyridines / Q000138:chemical synthesis / Q000737:chemistry*; D004952:Esters; D012997:Solvents / Q000737:chemistry
chemical_list: D000588:Amines; D002264:Carboxylic Acids; D004095:Dihydropyridines; D004952:Esters; D012997:Solvents; C038806:1,4-dihydropyridine
keywords: 1,4-dihydropyridines; 1,5,7-triazabicyclo[4.4.0]dec-5-ene; aminolysis; carbamoylmethyl esters; cyclic amines; ethoxycarbonylmethyl esters; secondary amines