The remarkable effect of 7-amino substituents on the reactivity of 4-nitrobenzofurazans with nucleophiles
Bibliographic record
Abstract
The reactions of four 4-nitrobenzofurazans (4a4d) substituted at the 7 position with (a) N-ethyl, (b) N-butyl, (c) piperidino, or (d) pyrrolidino groups have been examined with sulfite ions and with hydroxide ions in waterDMSO (80:20, v/v). Addition of sulfite at the 5 position gives σ adducts with equilibrium constants ca. 10 5 lower than that for the formation of the corresponding adduct from 4-nitrobenzofurazan. These reductions are attributed to the stabilization of the parent molecules 4a4d by conjugative interaction between the 4 and 7 substituents. In alkaline solution, 4a and 4b yield the conjugate bases while 4c and 4d suffer nucleophilic substitution to give 7-hydroxy-4-nitrobenzofurazan. Reactivity here is relatively high because of the iminium ion character of the substrates. Key words: benzofurazans, σ adducts, nucleophilic reactivity, substitution.
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 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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 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) | 0.001 | 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".