Synthesis of novel coumarin and benzocoumarin derivatives and their biological and photophysical studies
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Abstract magnified image Several derivatives of coumarin‐3 N ‐carboxamides ( 3‐21 ) have been prepared via the reaction of the coumarin‐3‐carbonyl chloride ( 1 ) with a number of nucleophiles. Novel double‐headed coumarin‐3 N ‐carboxamides ( 26‐33 ) were also produced using the same method. The Pechmann‐Duisberg reaction was applied to prepare new benzo[ f ]‐ benzo[ h ]coumarins and 4‐(chloromethyl)‐pyrano[3,2‐ c ]coumarin‐2‐one ( 36‐42 ). The reaction of 1‐chloromethylbenzo[ f ]coumarins ( 36 ) with cyanide anion under different reaction conditions was also investigated in order to assess its suitability for nucleophilic substitution reactions as well as ring transformation products ( 43‐49 ). Synthesis of 1‐((benzo[ d ]thiazol‐2‐yl)methyl)‐9‐hydroxybenzo[ f ]coumarin ( 50 ) represented the first example of methylene bridge‐head heterocyclecontaining benzo[ f ]coumarin. Some of the newly prepared coumarins exhibited anti‐bacterial activity against Gram Positive and Gram negative bacteria. Compound 36d was found to be active against all the screened bacteria. Photophysical studies were performed on selected fluorescent benzo[ f ]‐ and benzo[ h ]coumarin and the quantum yields were also calculated. All new compounds were characterized by IR, MS, 1 H and 13 C NMR, as well as elemental analysis.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it