Charles F. Beam

Synthesis of Pyrazoles by the Condensation of C(α)- and Trianions with Esters

Abstract In addition to our previous papers2,3 on the preparation of pyrazoles from the C(α), N-dianions of phenylhydrazones and C(α), N, N-trianions of hydrazones, we wish to report preliminary results on (I) the preparation and condensation of methylhydrazone dianions with methyl benzoate followed by acid cyclization, (II) the condensation of the dianions of phenylhydrazone with methylformate, and the preparation and condensation of the trianions of cyclopentanone (III) and α - tetralone (IV) hydrazones.

The Preparation of New C(α)-Dianions

Abstract For more than a decade, Hauser et. al. carried out rather extensive investigations on the preparation and reactions of the multiple anions of β -diketones and related materials. Once the conditions for the preparation of a particular multiple anion seemed established, three reactions were usually attempted with the new multiple anion: alkylations with reagents such as benzyl chloride2, Aldol-type condensations with aldehydes or ketones3 such as benzaldehyde and benzophenone, and Claisen-type condensations with esters such as methyl benzoate4. Other electrophilic reagents, such as nitriles5 and isocyanates6, were also condensed with certain of these multiple anions in selective situations; however, the alkylations, acylations, and carbonyl additions received the greatest amount of attention7. In some cases only one of the three types of reactions (Aldol) worked well8; however this did not mean that conditions could not be found for the other two reaction types. In addition, the synthetic potential...

A new method for the preparation of 2-carhoalkoxypyrazolo [5,1 -B] quinazolin-9(1H)ones

Anthranilic acid hydrazides were condensed with acetylene diesters, and the intermediate adduets were identified as aeylhydrazones of oxalacetic diester. These anthranilic hydrazones could be thermally cyclized to 2-carboalkoxypyrazolo[5,1-b] quinazolin-9(1H)ones.

The Preparation and Reactions of Anions of Certain Schiff Bases

Abstract We have recently reported the facile preparation of C(α)-multiple anions of oximes2, phenylhydrazones3, hydraxones4, and acylhydrazones5. In each case the C(α)-carbanion reacted with electrophilic reagents such as aromatic esters, an alphatic diester6, acid chlorides7, aldehydes8, ketones9, carbon dioxide10, and nitriles11 (Scheme I).