ChemInform Abstract: Hydrolysis Studies of Chalcogenopyrylium Trimethine Dyes. Part 1. Product Studies in Alkaline Solution (pH ≥ 8) under Anaerobic and Aerobic Conditions.
✍ Scribed by D. N. YOUNG; M. R. DETTY
- Publisher
- John Wiley and Sons
- Year
- 2010
- Weight
- 38 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0931-7597
No coin nor oath required. For personal study only.
✦ Synopsis
Hydrolysis Studies of Chalcogenopyrylium Trimethine Dyes. Part 1. Product Studies in Alkaline Solution (pH ≥ 8) under Anaerobic and Aerobic Conditions.
-The outcome of the hydrolysis of chalcogenopyrylium trimethine dyes is found to depend on the present heteroatoms, the presence or absence of oxygen, oxygen concentration, and pH value. Under anaerobic and aerobic conditions at pH 8 the dyes (VI), which contain a pyrylium ring, lead to the ring opening products (VII), derived from addition of hydroxide to the 2-position. In the absence of oxygen, the symmetrical dyes (VIII) and unsymmetrical dyes give products derived from attack at the 2-position and the central carbon of the trimethine bridge, while the analogue (I) only affords products derived from attack at the central carbon of the bridge. Under aerobic conditions formation of ketones of type (IV) and (XII) and rearrangement to 5-membered nonmetal heterocycles (see (V) and (XIII)) is also obtained. -(YOUNG, D.