Abstract
HPLC, 1H-NMR, MS and product analysis showed that pyridoxal hydrochloride was solvolyzed in methanol to form pyridoxal monomethylacetal. The reaction followed first order kinetics with the rate constant of 1.45 x 10-4 s-1 at 40 °C. The rate was not appreciably enhanced in the presence of an excess amount of HCl. The reaction was greatly retarded by addition of an equimolar amount of KOH. The results showed that the pyridinium-phenol species of pyridoxal hemiacetal is reactive. The reaction is responsible for the 'aging' of alcoholic solutions of pyridoxal, which has caused poor reproducibility of the kinetic data for the formation of Schiff bases with amino acids.
| Original language | English |
|---|---|
| Pages (from-to) | 1019-1022 |
| Number of pages | 4 |
| Journal | Chemical and Pharmaceutical Bulletin |
| Volume | 41 |
| Issue number | 6 |
| Publication status | Published - 1993 |
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ASJC Scopus subject areas
- Chemistry(all)
- Organic Chemistry
- Drug Discovery
- Pharmacology
Cite this
Solvolysis of pyridoxal hydrochloride in alcohols. / Itoh, Yoshiko; Yoda, R.; Matsushima, Y.
In: Chemical and Pharmaceutical Bulletin, Vol. 41, No. 6, 1993, p. 1019-1022.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Solvolysis of pyridoxal hydrochloride in alcohols
AU - Itoh, Yoshiko
AU - Yoda, R.
AU - Matsushima, Y.
PY - 1993
Y1 - 1993
N2 - HPLC, 1H-NMR, MS and product analysis showed that pyridoxal hydrochloride was solvolyzed in methanol to form pyridoxal monomethylacetal. The reaction followed first order kinetics with the rate constant of 1.45 x 10-4 s-1 at 40 °C. The rate was not appreciably enhanced in the presence of an excess amount of HCl. The reaction was greatly retarded by addition of an equimolar amount of KOH. The results showed that the pyridinium-phenol species of pyridoxal hemiacetal is reactive. The reaction is responsible for the 'aging' of alcoholic solutions of pyridoxal, which has caused poor reproducibility of the kinetic data for the formation of Schiff bases with amino acids.
AB - HPLC, 1H-NMR, MS and product analysis showed that pyridoxal hydrochloride was solvolyzed in methanol to form pyridoxal monomethylacetal. The reaction followed first order kinetics with the rate constant of 1.45 x 10-4 s-1 at 40 °C. The rate was not appreciably enhanced in the presence of an excess amount of HCl. The reaction was greatly retarded by addition of an equimolar amount of KOH. The results showed that the pyridinium-phenol species of pyridoxal hemiacetal is reactive. The reaction is responsible for the 'aging' of alcoholic solutions of pyridoxal, which has caused poor reproducibility of the kinetic data for the formation of Schiff bases with amino acids.
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UR - http://www.scopus.com/inward/citedby.url?scp=0027169693&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0027169693
VL - 41
SP - 1019
EP - 1022
JO - Chemical and Pharmaceutical Bulletin
JF - Chemical and Pharmaceutical Bulletin
SN - 0009-2363
IS - 6
ER -