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Record W7140406344 · doi:10.1333/s00897172762aa

An Improved Laboratory Synthesis of Betaine-30

2017· article· en· W7140406344 on OpenAlex
Magrieta Snyman, Brian P. Rempel

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueThe Chemical Educator · 2017
Typearticle
Languageen
FieldChemistry
TopicVarious Chemistry Research Topics
Canadian institutionsUniversity of Alberta
Fundersnot available
KeywordsAcetophenoneSolventYield (engineering)Polarity (international relations)Sodium dithioniteHydrogen

Abstract

fetched live from OpenAlex

Empirical solvent polarity can be measured with betaine-30, a highly solvatochromatic compound meaning that solutions of betaine-30 in different solvents are different colors in response to the polarity of the solvent. These solutions are excellent tools to visualize solvent polarity, a concept that underlies the important role solvent plays in a chemical reaction or process. By showing how the solution color changes with solvent polarity, students can draw an analogy with non-visible properties that also depend on solvent polarity such as reaction rates. The synthesis of betaine-30 is a straightforward four-step convergent synthesis starting from inexpensive starting materials: 1,3-diphenylpropenone (chalcone), acetophenone and 2,6-diphenylphenol. Herein, an updated and improved synthesis of betaine-30 is presented that is quick, easy, high-yielding, and can be readily accomplished by senior undergraduate organic chemistry students. In particular, a better method for preparation of the first intermediate, 2,4,6-triphenylpyrylium hydrogen sulfate from acetophenone and 1,3- diphenylpropenone (chalcone), is described. As well, nitrosylation of 2,6-diphenylphenol followed by reduction with sodium dithionite produces 4-amino-2,6-diphenylphenol in an efficient reaction sequence. Finally, the greater purity of the intermediates leads to a higher yield for the final coupling to form pure betaine-30.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.002
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesInsufficient payload (model declined to judge)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.011
Threshold uncertainty score0.999

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.002
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.001
Scholarly communication0.0000.000
Open science0.0020.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0020.000

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.

Opus teacher head0.015
GPT teacher head0.310
Teacher spread0.295 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it