Oxazoline chemistry part III. Synthesis and characterisation of [2‐(2′‐anilinyl)‐2‐oxazolines] and some related compounds
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Bibliographic record
Abstract
Abstract The syntheses and characterisation of a series of chiral and achiral 2‐(aminophenyl)‐2‐oxazolines and some related compounds is reported. All of the derivatives have been produced by a one‐step procedure involving the treatment of isatoic anhydride ( i.e. [2 H ]‐3, 1‐benzoxazine‐[1 H ‐2,4‐dione: 1 ) or its 5‐chloro analogue with a slight excess of appropriate amino‐alcohols. In most cases, anhydrous ZnCl 2 is shown to be an effective Lewis acid catalyst for this reaction at reflux temperature in high boiling aromatic solvents (PhCl or PhMe). Oxazolines have been readily formed using rac ‐2‐amino‐1‐butanol, ( S )‐phenylglycinol, 2‐methyl‐2‐amino‐1‐propanol and (1S,2R) or (IR,2S)‐cis ‐ 1 ‐amino‐2‐indanol; yields range from 85% to 22%. The use of aminoalcohols such as 2‐ethanolamine, (±)‐2‐amino‐1‐phenyl‐1‐propanol or 3‐amino‐1‐propanol (to give the corresponding 4,5‐dihydro‐1,3‐oxazine) results in poor yields. The use of other Lewis acid catalysts (silicic acid, Cd(acac) 2 ·2H 2 O, CuCl 2 ·2H 2 O, InCl 3 ) or higher temperatures did not improve the yields with these latter two substrates. Benzoxazoles and N‐substituted benzoxazoles can also be obtained in reasonable yields from 1 using 2‐aminophenol (36%) or 2‐amino‐3‐hydroxypyridine (45%).
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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 it