Quinazolin-4(3<i>H</i>)-ones and 5,6-Dihydropyrimidin-4(3<i>H</i>)-ones from β-Aminoamides and Orthoesters
Quinazolin-4(3<i>H</i>)-ones have been prepared in one step from 2-aminobenzamides and orthoesters in the presence of acetic acid. Simple 2-aminobenzamides were easily converted to the heterocycles by refluxing in absolute ethanol with 1.5 equivalents of the orthoester and 2 equivalents...
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MDPI AG
2018-11-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/23/11/2925 |
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doaj-3cdee7f608af4488aa931d190d88eb532020-11-25T00:32:58ZengMDPI AGMolecules1420-30492018-11-012311292510.3390/molecules23112925molecules23112925Quinazolin-4(3<i>H</i>)-ones and 5,6-Dihydropyrimidin-4(3<i>H</i>)-ones from β-Aminoamides and OrthoestersJoshua T. Gavin0Joel K. Annor-Gyamfi1Richard A. Bunce2Department of Chemistry, Oklahoma State University, Stillwater, OK 74078-3071, USADepartment of Chemistry, Oklahoma State University, Stillwater, OK 74078-3071, USADepartment of Chemistry, Oklahoma State University, Stillwater, OK 74078-3071, USAQuinazolin-4(3<i>H</i>)-ones have been prepared in one step from 2-aminobenzamides and orthoesters in the presence of acetic acid. Simple 2-aminobenzamides were easily converted to the heterocycles by refluxing in absolute ethanol with 1.5 equivalents of the orthoester and 2 equivalents of acetic acid for 12⁻24 h. Ring-substituted and hindered 2-aminobenzamides as well as cases incorporating an additional basic nitrogen required pressure tube conditions with 3 equivalents each of the orthoester and acetic acid in ethanol at 110 °C for 12⁻72 h. The reaction was tolerant towards functionality on the benzamide and a range of structures was accessible. Workup involved removal of the solvent under vacuum and either recrystallization from ethanol or trituration with ether-pentane. Several 5,6-dihydropyrimidin-4(3<i>H</i>)-ones were also prepared from 3-amino-2,2-dimethylpropionamide. All products were characterized by melting point, FT-IR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, and HRMS.https://www.mdpi.com/1420-3049/23/11/2925quinazolin-4(3<i>H</i>)-ones5,6-dihydropyrimidin-4(3<i>H</i>)-onesheterocycle synthesis2-aminobenzamidesorthoesters |
| collection |
DOAJ |
| language |
English |
| format |
Article |
| sources |
DOAJ |
| author |
Joshua T. Gavin Joel K. Annor-Gyamfi Richard A. Bunce |
| spellingShingle |
Joshua T. Gavin Joel K. Annor-Gyamfi Richard A. Bunce Quinazolin-4(3<i>H</i>)-ones and 5,6-Dihydropyrimidin-4(3<i>H</i>)-ones from β-Aminoamides and Orthoesters Molecules quinazolin-4(3<i>H</i>)-ones 5,6-dihydropyrimidin-4(3<i>H</i>)-ones heterocycle synthesis 2-aminobenzamides orthoesters |
| author_facet |
Joshua T. Gavin Joel K. Annor-Gyamfi Richard A. Bunce |
| author_sort |
Joshua T. Gavin |
| title |
Quinazolin-4(3<i>H</i>)-ones and 5,6-Dihydropyrimidin-4(3<i>H</i>)-ones from β-Aminoamides and Orthoesters |
| title_short |
Quinazolin-4(3<i>H</i>)-ones and 5,6-Dihydropyrimidin-4(3<i>H</i>)-ones from β-Aminoamides and Orthoesters |
| title_full |
Quinazolin-4(3<i>H</i>)-ones and 5,6-Dihydropyrimidin-4(3<i>H</i>)-ones from β-Aminoamides and Orthoesters |
| title_fullStr |
Quinazolin-4(3<i>H</i>)-ones and 5,6-Dihydropyrimidin-4(3<i>H</i>)-ones from β-Aminoamides and Orthoesters |
| title_full_unstemmed |
Quinazolin-4(3<i>H</i>)-ones and 5,6-Dihydropyrimidin-4(3<i>H</i>)-ones from β-Aminoamides and Orthoesters |
| title_sort |
quinazolin-4(3<i>h</i>)-ones and 5,6-dihydropyrimidin-4(3<i>h</i>)-ones from β-aminoamides and orthoesters |
| publisher |
MDPI AG |
| series |
Molecules |
| issn |
1420-3049 |
| publishDate |
2018-11-01 |
| description |
Quinazolin-4(3<i>H</i>)-ones have been prepared in one step from 2-aminobenzamides and orthoesters in the presence of acetic acid. Simple 2-aminobenzamides were easily converted to the heterocycles by refluxing in absolute ethanol with 1.5 equivalents of the orthoester and 2 equivalents of acetic acid for 12⁻24 h. Ring-substituted and hindered 2-aminobenzamides as well as cases incorporating an additional basic nitrogen required pressure tube conditions with 3 equivalents each of the orthoester and acetic acid in ethanol at 110 °C for 12⁻72 h. The reaction was tolerant towards functionality on the benzamide and a range of structures was accessible. Workup involved removal of the solvent under vacuum and either recrystallization from ethanol or trituration with ether-pentane. Several 5,6-dihydropyrimidin-4(3<i>H</i>)-ones were also prepared from 3-amino-2,2-dimethylpropionamide. All products were characterized by melting point, FT-IR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, and HRMS. |
| topic |
quinazolin-4(3<i>H</i>)-ones 5,6-dihydropyrimidin-4(3<i>H</i>)-ones heterocycle synthesis 2-aminobenzamides orthoesters |
| url |
https://www.mdpi.com/1420-3049/23/11/2925 |
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