ISSN:
1573-8353
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Condensation of 2, 4-diacetylphenol with diethyl oxalate serves as a basis for preparing 2-carbethoxy- and 2-carboxy-6-acetylchromones (I, II), 2-carbethoxy-6-ethoxyoxalyacetylchromone (V), and 2-carboxy-6-hydroxyoxalylacetylchromone (VI). The Mannich reaction is used to synthesize 6-(ω-dialkylaminopropionyl)-2-carboxychromones (VII, VIII) from compound I. Reaction of chromone-2-carbonyl chloride with enamines prepared from cyclohexanone and tetrahydrothiopyrone-4- gives syntheses of 2-(chromonoyl-2)cyclohexanone (III) and 3-(chromonoyl-2)tetrahydrothiopyrone-4 (IV). Hydrazine hydrate and compound III give the pyrazole derivative IX, while hydrazine hydrate and compound IV give pyrazole derivative X along with pyrazolylpyrazole derivative XI, which results from a second molecule of hydrazine hydrate opening the chromone ring.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00481575
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