909-59-1

Usage

InChI:InChI=1/C20H17N5O2/c1-13-17(19(26)24(22-13)15-9-5-3-6-10-15)21-18-14(2)23-25(20(18)27)16-11-7-4-8-12-16/h3-12,17H,1-2H3/b21-18+

Upstream product

• 881-05-0 3-Methyl-1-phenyl-2-pyrazoline-4,5-dione 
• 99694-71-0 4-aminoantipyrine 
• 1080-89-3 4-hydroxyimino-3-methyl-1-phenyl-2-pyrazolin-5-one 
• 74-88-4 methyl iodide 
• 58-15-1 aminopyrine 
• 74451-57-3 (E)-5,5'-dimethyl-2,2'-diphenyl-2H,2'H-[4,4']bipyrazolylidene-3,3'-dione 
• 56634-85-6 4-isonitroso-3-methyl-1-phenyl-2-pyrazolin-5-one 
• 53847-70-4 3-methyl-5-oxo-1-phenyl-4-phenyldiazenyl-1,2-diazacyclopent-3-ene 
• 89-25-8 edaravone 
• 130593-32-7 6-amino-1,4,5,6-tetrahydro-5-imino-3-methyl-1,4-diphenylpyrazolo<4',3':5,6>pyrano<2,3-d>pyrimidine 

Downstream Products

• 53847-70-4 3-methyl-5-oxo-1-phenyl-4-phenyldiazenyl-1,2-diazacyclopent-3-ene 

Relevant academic research and scientific papers

Rubazonic Acids and Their Synthesis

Rubazonic acids are a class of dyes that are long-known, but studies on their syntheses and uses are rare. We now describe an experimentally simple and highly practical one-pot procedure for their synthesis starting from easily accessible 1H-pyrazol-5(4H)-ones. This protocol provides direct access to a broad range of the desired rubazonic acid derivatives through oxidative diazidation combined with a reductive work-up, without the need to isolate the potentially hazardous diazido compounds generated en route the target compounds. We also show how more challenging variants of rubazonic acid are efficiently prepared using an alternative two-step procedure and controlled hydrogenation conditions.

Reactivity of 3-methyl-1-phenyl-2-pyrazoline-4,5-dione with amines

Reaction of 3-methyl-1-phenyl-2-pyrazoline-4,5-dione (1) with amine or diamine derivatives has been investigated.Primary aliphatic amines or diamines with α-hydrogens react with 1 to give rubazonic acid (7), while 1 with amines substituted in α-position addition products are formed which yield Schiff bases an heating.Aromatic o-diamines react with 1 to give different heterocyclic derivatives.

Synthesis of Various Pyrazolopyranotriazolopyrimidines and Pyrazolopyranopyrimidotriazines

A number of heterocyclic compounds 5-13 were prepared by the reaction of 6-amino-1,4,5,6-tetrahydro-5-imino-3-methyl-1,4-diphenylpyrazolopyranopyrimidine (3) with ethyl 2-cyano-3-ethoxy-2-propenoate, ethoxymethylenemalononitrile, ethyl c

Reactions of 4-Isonitroso-3-methyl-2-pyrazolin-5-one Derivatives

4-Isonitroso-3-methyl-2-pyrazolin-5-one (Ia) or its 1-phenyl analogue (Ib) reacts readily with diazoalkanes or the corresponding alkyl halides to yield exclusively the 4-alkyl derivatives (II), no oxazoles or the corresponding nitrones are formed.The isonitroso derivatives (Ia, b) undergo condensation with primary aliphatic amines or amino acids to give rubazonic acid derivatives (Va, b).