Syntheses of the phosphodiesterase‐4 inhibitors [<sup>11</sup>C]Ro 20‐1724, R‐, R/S‐ and S‐[<sup>11</sup>C]rolipram
Bibliographic record
Abstract
Abstract The high affinity and selective cAMP‐specific phosphodiesterase‐4 inhibitors Ro 20‐1724, R‐, R/S‐ and S‐rolipram were labeled with 11C by O‐[11C]methylation of their respective phenolic precursors using [11C]methyl iodide. The desmethyl precursor of Ro 20‐1724 was prepared by selective dealkylation with iodotrimethylsilane, whereas, dealkylation of racemic rolipram was not selective and yielded several products. Enantiomeric separation of R‐ and S‐desmethylrolipram was carried out by chiral semi‐preparative high performance liquid chromatography. The final 11C‐labeled products were prepared in high radiochemical purity (>99%), yields (45‐75%, decay‐corrected) and specific activities [18.5‐92.5 GBq/µmol], within 30 min from end‐of‐bombardment. Copyright © 2001 John Wiley & Sons, Ltd.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.003 |
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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".