Cyclization Modes in Anilides of <i>N</i>-Protected 3-Oxo-4-phenylaminobutyric Acid Under Knorr Conditions
Anilides of 3-oxo-4-phenylaminobutyric acid with Troc or COOEt protection at the phenylamino group undergo competing cyclization processes in neat polyphosphoric acid at 80 °C. Depending on the protecting group and the duration of the process, three main products in different ratios are formed. Alon...
Saved in:
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-12-01
|
| Series: | Molbank |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-8599/2024/4/M1933 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850086855289077760 |
|---|---|
| author | Plamen Angelov Yordanka Mollova-Sapundzhieva |
| author_facet | Plamen Angelov Yordanka Mollova-Sapundzhieva |
| author_sort | Plamen Angelov |
| collection | DOAJ |
| description | Anilides of 3-oxo-4-phenylaminobutyric acid with Troc or COOEt protection at the phenylamino group undergo competing cyclization processes in neat polyphosphoric acid at 80 °C. Depending on the protecting group and the duration of the process, three main products in different ratios are formed. Along with the quinolin-2-ones, resulting from the classic Knorr cyclization, an indole derivative and a spirocyclic product have also been obtained from the COOEt-protected substrate. It has been demonstrated that the obtained indole derivative is capable of further dearomative spirocyclization under the studied conditions. |
| format | Article |
| id | doaj-art-22d7a53eb69d4401a3e958622d3a6c23 |
| institution | DOAJ |
| issn | 1422-8599 |
| language | English |
| publishDate | 2024-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molbank |
| spelling | doaj-art-22d7a53eb69d4401a3e958622d3a6c232025-08-20T02:43:20ZengMDPI AGMolbank1422-85992024-12-0120244M193310.3390/M1933Cyclization Modes in Anilides of <i>N</i>-Protected 3-Oxo-4-phenylaminobutyric Acid Under Knorr ConditionsPlamen Angelov0Yordanka Mollova-Sapundzhieva1Department of Organic Chemistry, University of Plovdiv Paisii Hilendarski, 24 Tsar Asen Str., 4000 Plovdiv, BulgariaDepartment of Organic Chemistry, University of Plovdiv Paisii Hilendarski, 24 Tsar Asen Str., 4000 Plovdiv, BulgariaAnilides of 3-oxo-4-phenylaminobutyric acid with Troc or COOEt protection at the phenylamino group undergo competing cyclization processes in neat polyphosphoric acid at 80 °C. Depending on the protecting group and the duration of the process, three main products in different ratios are formed. Along with the quinolin-2-ones, resulting from the classic Knorr cyclization, an indole derivative and a spirocyclic product have also been obtained from the COOEt-protected substrate. It has been demonstrated that the obtained indole derivative is capable of further dearomative spirocyclization under the studied conditions.https://www.mdpi.com/1422-8599/2024/4/M1933indolesquinolin-2-onesknorr quinolone synthesisspirocyclesindole dearomative spirocyclization |
| spellingShingle | Plamen Angelov Yordanka Mollova-Sapundzhieva Cyclization Modes in Anilides of <i>N</i>-Protected 3-Oxo-4-phenylaminobutyric Acid Under Knorr Conditions Molbank indoles quinolin-2-ones knorr quinolone synthesis spirocycles indole dearomative spirocyclization |
| title | Cyclization Modes in Anilides of <i>N</i>-Protected 3-Oxo-4-phenylaminobutyric Acid Under Knorr Conditions |
| title_full | Cyclization Modes in Anilides of <i>N</i>-Protected 3-Oxo-4-phenylaminobutyric Acid Under Knorr Conditions |
| title_fullStr | Cyclization Modes in Anilides of <i>N</i>-Protected 3-Oxo-4-phenylaminobutyric Acid Under Knorr Conditions |
| title_full_unstemmed | Cyclization Modes in Anilides of <i>N</i>-Protected 3-Oxo-4-phenylaminobutyric Acid Under Knorr Conditions |
| title_short | Cyclization Modes in Anilides of <i>N</i>-Protected 3-Oxo-4-phenylaminobutyric Acid Under Knorr Conditions |
| title_sort | cyclization modes in anilides of i n i protected 3 oxo 4 phenylaminobutyric acid under knorr conditions |
| topic | indoles quinolin-2-ones knorr quinolone synthesis spirocycles indole dearomative spirocyclization |
| url | https://www.mdpi.com/1422-8599/2024/4/M1933 |
| work_keys_str_mv | AT plamenangelov cyclizationmodesinanilidesofiniprotected3oxo4phenylaminobutyricacidunderknorrconditions AT yordankamollovasapundzhieva cyclizationmodesinanilidesofiniprotected3oxo4phenylaminobutyricacidunderknorrconditions |