Pyrazoles pyrano

N-Phenylpyrazolone 194a adds to indolones 213 to form spiro pyrano-pyrazoles 226, which possess herbicidal activity (88JIC277) (Scheme 86). 

Wesentlich bessere Ergebnisse erhalt man mit einem Pyrazol-Dienpartner, dessen Dien-Teil Teil eines Pyrans ist. Dieses Pyrano-pyrazol wird auf einfache Weise durch Kondensation und nachfolgende Addition von l,3-Diphenyl-5-hydroxy-pyrazol mit zwei Molekiilen Aceton her-gcstellt465. Aus diesem Zwischenprodukt konnen durch Reaktion mit starken Dienophilen (Bu-tindisaure-diester) hochsubstituierte lH-Indazole hergestellt werden465 469 z. B. ... 

K. Kanagaraj, K. Pitchumani, Tetrahedron Lett. 2010, 51, 3312-3316. Solvent-free multicomponent synthesis of pyrano-pyrazoles per-6-amino-p-cyclodextrin as a remarkable catalyst and host. 

S.Bhavanarushi, V. Kanakaiah, E. Yakaiah, V. Saddanapu, A. Addlagatta, V.J. Rani, Synthesis, cytotoxic, and DNA binding studies of novel fluorinated condensed pyrano pyrazoles. Med. Chem. Res. 22 (2013) 2446-2454. 

Litvinov YM, Shestopalov AA, Rodinovskaya LA, Shestopalov AM (2009) New convenient four-component synthesis of 6-amino-2,4-dihydropyrano 2,3-c pyrazol-5-carbonitriles and one-pot synthesis of 6 -aminospiro (3H)-indol-3,4 -pyrano 2,3-c pyrazol -(lH)-2-on-5 -carbonitriles. J Comb Chem 11 914—919... 

In the case of 5-bromo-3,4-dimethyl-l-phenyl-l/f, 6//-pyrano[2,3-c]pyrazol-6-one (59), mixed acid nitration results not only in para substitution in the phenyl ring, but also in ipso attack at the 5-position to yield... 

The Pd-catalysed Miyaura-Suzuki coupling of aryltrifluoroborates with 4-tosyloxycoumarins in aqueous conditions offers an attractive route to 4-arylcoumarins <06TL1525> and 4-hydroxycoumarins have been converted into a mixture of predominantly thiopyrano[5, 4 3,4]- pyrano[5,6-c]coumarins and [6,5-c]chromones in a one-pot tandem Knoevenagel - HDA sequence with an S-prenylated 1-phenyl-lff-pyrazole-4-carbaldehyde <06TL2265>. The benzopyrano[4,3-c]benzopyranone system can be obtained from 3-aryl-4-methylcoumarins by deprotonation of the methyl function and subsequent elaboration <06TL5909>. 

Many reports of fused-pyrazole heterocycles have been published. A high throughput synthesis of pyrazolopyrimidines has been achieved by copper(I)-catalyzed cyclizations <05H(65)1821>. A simple synthesis of 6-phenylpyrano[2,3-c]pyrazol-4(lf/)-ones has been reported <05S2583>. A solvent-free, one-pot synthesis of pyrano[2,3-c]pyrazole derivatives in the presence of potassium fluoride and grinding has been disclosed <05SC2509>. Reactions of... 

The compound (102.3), used in the synthesis of a fused pyridine in Section II. I, may also be cyclized to pyrano- or thiopyrano-pyrazole by heating with phosphorus pentoxide-PPA or phosphorus pentasulphide. The presence of ethanol or acetic acid retards the reaction. 

Im 2-Methyl-7-oxo-5-phenyl-2,7-dihydro- wird der Pyron-Ringmit 0,1 N Kalilauge quantitativ aufgespalten1853 ... 

Brom-5-hydroxy-3-methyl-lH-pyrazol reagiert mit Aryliden-malonsaure-ethylester-nitrilen oder -dinitrilen unter basischen Bedingungen (2 h RuckfluB Ethanol Piperidin-Zusatz) zu 4-Aryl-5-cyan-3-methyl-6-oxo-l, 6-dihydro-[Pg.667]

In Analogic zum obengenannten Ringschlufi (S. 667) werden aus 4-Carboxy-5-iod-lH-pyrazolen mit Kup-feracetyleniden l,4-Dihydro- erhalten z. B.2086 ... 

Dimethoxycarbonyl-l,3-diphenyl-4-methyl-lH-indazol4< q Eine Losung von 3,16 g (10 mmol) 1,3-Diphe-nyl-4,6,6-trimethyl-1.6-dihydro- und 1,92 g (15 mmol) Butindisaure-dimethylester in 100 mltrockenem DMF wird 12 h unter Riickflufi erhitzt. Das Losungsmittel wird i. Vak. bei 20 entfernt und der dunkelbraune olige Riickstand aus 2-Propanol/Aceton (10 1) umkristallisiert Ausbeute 3,28 g (82%) Schmp. 180-182J. 

Dimcthoxycarbonyl-l,3-diphenyl-4-methyl-aus l,3-Diphcnyl-4,6,6-trimethyl-l,6-dihydro-[Pg.1197]

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