Synthesis of dialkyl 1,4‐dihydro‐2,6‐dimethylpyridine‐3,5‐dicarboxylates and alkyl 1,4‐dihydro‐2,6‐dimethyl‐3‐nitropyridine‐5‐carboxylates possessing a c‐4 2,4‐dioxo‐1,2,3,4‐tetrahydropyrimidin‐5‐yl (uracil) substituent to determine calcium channel modulation structure‐activity relationships
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 The Hantzsch condensation of 5‐formyluracil ( 1 ) with methyl, isopropyl or isobutyl acetoacetate (2a‐c) in the presence of ammonium hydroxide afforded the respective dialkyl 1,4‐dihydro‐2,6‐dimethyl‐4‐(2,4‐dloxo‐1,2,3,4,‐tetrahydropyrimidin‐5‐yl)pyridine‐3,5‐dicarboxylate (3a‐c). A group of alkyl 1,4‐dihydro‐2,6‐dimethyl‐3‐nitro‐4‐(2,4‐dioxo‐1,2,3,4‐tetrahydropyrimidin‐5‐yl)pyridine‐5‐carboxylates (6a‐c) were also prepared using a modified Hantzsch reaction that involved the condensation of 5‐formyluracil with nitroacetone and either methyl, isopropyl or isobutyl 3‐aminocrotonate (5a‐c). A C‐4 2,4‐dioxo‐1,2,3,4‐tetrahydropyrimidin‐5‐yl substituent is not a suitable bioisostere for the traditional C‐4 aryl or heteroaryl substituents present in 1,4‐dihydropyridine calcium channel modulators since diisopropyl 1,4‐dihydro‐2,6‐dimemyl‐4‐(2,4‐dioxo‐1,2,3,4‐tetrahydropyrimidin‐5‐yl)pyridine‐3,5‐dicarboxylate (3b) and isobutyl 1,4‐dihydro‐2,6‐dimethyl‐3‐nitro‐4‐(2,4‐dloxo‐1,2,3,4‐tetrahydropyrimidin‐5‐yl)pyridine‐5‐carboxylate (6c) did not exhibit any in vitro calcium channel antagonist activity using a guinea pig smooth muscle calcium channel antagonist assay, or a guinea pig left atrium calcium channel agonist (positive inotropic) assay.
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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 | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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