Bibliographic record
Abstract
[23708-48-7] C4H8Br2Mg2 (MW 264.53) InChI = 1S/C4H8.2BrH.2Mg/c1-3-4-2;;;;/h1-4H2;2*1H;;/q;;;2*+1/p-2 InChIKey = OMQMAXADYGBHEG-UHFFFAOYSA-L (constructing block agent: transformation of many functional groups into cyclopentane, spiro[4.4]nonane, and spiro[4.5]decane synthetic intermediates, and metallacycles) Solubility: sol THF, ether, and toluene. Form Supplied in: generally prepared in THF. Analysis of Reagent Purity: titration.2 Preparative Method: the following preparative method was found to be of general use for the preparation of various 1,n-bis(bromomagnesio)alkanes (n = 4–6), as well as for primary, secondary, and unsaturated di-Grignard reagents, from the corresponding dibromides.3 1,4‐Dibromobutane (69 mmol) dissolved in anhydrous THF (150 mL) is added dropwise to Magnesium turnings (150 mmol) covered with a few mL of the dibromide solution. The exothermic reaction starts within a few minutes and is controlled by the rate of addition of the dibromide, avoiding excessive heating. After an additional 2 to 6 h period, the formation of the reagent is completed (yield ∼90%) (eq 1). However, for 1,3-bis(bromomagnesio)propane, this procedure is not suitable, as the elimination product is mostly formed. Therefore, one should refer to the appropriate literature for that particular case.4 (1) Handling, Storage, and Precautions: solutions are highly flammable; must be stored in the absence of proton sources, carbon acids, and oxygen. Flasks and Schlenk tubes should be flushed with dry Ar or N2. Handle with standard syringe technique to prevent contact of the solutions with oxygen and moisture. Solutions can be stored at 0 °C for months.
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.
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) | 0.015 | 0.008 |
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".