No abstract

No abstract

No abstract

Dimethyl tetrahydropyranyloxymalonate reacts with hydrazobenzene to give 3 : S-dioxo-1 : 2-diphenyl-4-tetrahydropyranyloxypyrazolidine. Removal of the tetrahydropyranyl group afforded 4-hydroxy-3 : 6-dioxo-1 : 2diphenylpyrazolidine. A series of 4-alkoxy-3 : S-dioxo-1 : 2-diphenylpyrazolidines has been prepared by interaction of alkoxymalonic esters with hydrazobenzene. 4-Alkoxy-3-hydroxy-1 : 2-diphenylpyrazolin-6-ones were isolated directly from condensations utilising diethyl methoxy-and ethoxymalonic esters; these are converted into the isomeric 4-alkoxy-3 : S-dioxo-1 : 2-diphenylpyrazolidines. Condensations of N-benzyl-N-rt-butyl-and Nbenzyl-N-methyl-aminomalonates with hydrazobenzene and debenzylation of the resultant products gave the corresponding 4-n-butylamino-and 4-methylamino-3 : S-dioxo-1 : 2-diphenylpyrazolidines.RECENT investigations into the anti-inflammatory activities of the 4-acyl-,l 4-alkyl-,2v and Paminoalkyl-3 : 6-dioxo-l : 2-diphenylpyrazolidines have emphasised the high degree of specificity associated with the phenylbutazone structure (I; R = Bun).Syntheses are described, below, of the hitherto unknown 4-hydroxy-analogue (I; R = OH) and certain Palkoxy-(I; R = OMe, OEt, OPr*, and OBu") and 4-alkylamino-3 : 5dioxo-1 : 2-diphenylpkazolidines (I11 ;

No abstract