5‐Chloro‐ <i>N</i> ‐(di‐ <i>tert</i> ‐butylphosphaneyl)‐ <i>N</i> ‐methylpyrazin‐2‐amine
Bibliographic record
Abstract
image [2981401‐76‐5] C 13 H 23 ClN 3 P (MW 287.77) InChI = 1S/C13H23ClN3P/c1‐12(2,3)18(13(4,5)6)17(7)11‐9‐15‐10(14)8‐16‐11/h8‐9H,1‐7H3 InChIKey = WNSRMVGRQQVGJQ‐UHFFFAOYSA‐N (ligand for gold‐catalyzed cross‐coupling reactions 1 ) Alternative Name(s): ClKarPhos. Solubility: soluble in CHCl 3 , DCM, DCE, Et 2 O, THF. Form Supplied in: light orange solid. Analysis of Reagent Purity: 1 H NMR (300 MHz, CDCl3) δ (ppm) 8.89 (dd, J = 4.5, 1.5 Hz, 1 H ), 8.05 (dd, J = 1.5, 0.7 Hz, 1 H ), 3.24 (s, 3 H ), 1.25 (d, J = 12.8 Hz, 18 H ). 13 C NMR (75 MHz, CDCl3) δ (ppm) 158.1 (d, J = 24.7 Hz), 139.9, 136.8 (d, J = 2.7 Hz), 134.6 (d, J = 36.9 Hz), 37.2 (d, J = 7.4 Hz), 36.2 (d, J = 27.8 Hz), 29.8 (d, J = 16.7 Hz). 31 P NMR (122 MHz, CDCl3) δ (ppm) 85.0 HRMS (ESI) Calculated for C 13 H 24 ClN 3 P + [M+H] + : 288.1391; found: m/z 288.1378. Preparative Methods 1 : a flame‐dried Schlenk flask was charged with the 5‐chloro‐ N ‐methylpyrazin‐2‐amine (65 mg, 0.45 mmol) and dry THF [0.2 M] under a nitrogen atmosphere. The resulting solution was cooled down to 0 °C before a solution of n ‐BuLi in hexane (0.18 mL, 0.45 mmol) was added dropwise. The reaction mixture was allowed to reach room temperature and was then stirred for 4 hours before t Bu 2 PCl (86 μL, 91 mg, 0.45 mmol) was added dropwise. At the end of the addition, the temperature was raised to 60 °C and the reaction mixture was stirred for 3 days (eq ). The solvent was then evaporated, and the crude residue was purified by flash column chromatography using a 10:1 hexanes:ethyl acetate mixture as the eluent. image Purification: purification by flash column chromatography in hexanes:ethyl acetate = 10:1. Handling, Storage, and Precautions: bench stable, long‐term storage under nitrogen atmosphere and refrigerate to prevent degradation.
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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 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| 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 | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.143 | 0.045 |
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".