ISSN:
0009-2940
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Reactions with Cyclobutenediones, XXXVII. Reactions of (2,5-Dimethoxyphenyl)phenyl-and Diphenylcyclobutenedione with Diazoalkanes. A Contribution to the Study of Isomerism of Possible 1-Pyrazolines(2,5-dimethoxyphenyl)phenylcyclobutenedione (7) reacts with diazomethane to give only 3a-(2,5-Dimethoxyphenyl)-4-methoxy-6-oxo-6a-phenyl-3,3a,6,6a-tetrahydrocyclopentapyrazole (8a). In glacial acetic acid 8a isomerizes to the 2-pyrazoline 9a. Diphenylcyclobutenedione (1) reacts with diazoethane to yield the diastereomeric 1-pyrazolines 10 and 11. These two compounds isomerize in glacial acetic acid to form the same 2-pyrazoline 12 and react with acetyl chloride to give the same N-acetyl derivative 13. In xylene 10 reacts to form the 4-ethoxy-3,6-dimethyl-1,5-diphenylbicyclo[3.1.0]hex-3-en-2-one (14), while in boiling tetrahydronaphthalene 10 gives two isomeric phenols 16 and 18.
Notes:
(2,5-Dimethoxyphenyl)phenylcyclobutendion (7) reagiert mit Diazomethan in Benzol ausschließlich zu 3a-(2,5-Dimethoxyphenyl)-4-methoxy-6-oxo-6a-phenyl-3,3a,6,6a-tetrahydrocyclopentapyrazol (8a). Dieses kann in Eisessig zum 2-Pyrazolin 9a umgelagert werden. Diphenylcyclobutendion (1) reagiert mit Diazoäthan zu zwei diastereomeren 1-Pyrazolinen 10 und 11. Beide ergeben in Eisessig das gleiche 2-Pyrazolin 12 sowie mit Acetylchlorid das N-Acetyl-Derivat 13. In Xylol wird 10 in das 4-Äthoxy-3,6-dimethyl-1,5-diphenylbicyclo[3.1.0]hex-3-en-2-on (14) und in Tetralin in die isomeren Phenole 16 und 18 übergeführt.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19751080508
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