Diethyl 1,4-Dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate
Bibliographic record
Abstract
[1149-23-1] C13H19NO4 (MW 253.29) InChI = 1S/C13H19NO4/c1-5-17-12(15)10-7-11(13(16)18-6-2)9(4)14-8(10)3/h14H,5-7H2,1-4H3 InChIKey = LJXTYJXBORAIHX-UHFFFAOYSA-N (reagent used as a source of hydride) Alternate Name: HEH; Hantzsch ester hydride; Hantzsch ester; Hantzsch dihydropyridine; 1,4-dihydropyridine. Physical Data: mp 175–180 °C, bright yellow solid.2 Large variations in the melting point have been reported depending on the method of synthesis and purification. Solubility: sol in most organic solvents. Form Supplied in: solid (95% purity). Analysis of Reagent Purity: 1H NMR (1:1 DMSO/CDCl3, 400 MHz); δ 7.99 (s, 1H), 4.04 (q, J = 6.8 Hz, 4H), 3.09 (s, 2H), 2.09 (s, 6H), 1.20 (t, J = 7.2 Hz, 6H).13C NMR (CHCl3, 100 MHz): δ 168.3, 145.1, 99.7, 59.9, 25.0, 19.3, 14.7. FTIR (cm−1) (neat): 3346, 3108, 2953, 2924, 2854, 1697, 1646, 1506. Preparative Method: the reagent is most often prepared by a multicomponent reaction involving formaldehyde, ethyl acetoacetate, and ammonium acetate or ammonia.2-6 Purification: recrystallization from EtOH or flash chromatography with petroleum/ethyl acetate (7:3).4, 5 Handling, Storage, and Precautions: wear suitable gloves. Store compound in a dry container and in a cool place. Avoid contact with eyes and skin. Do not breathe dust.
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How this classification was reachedexpand
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 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, 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".