7 - -2H chromen-2-one

On the other hand, refluxing 9 in formic acid for 5 h afforded the N-formyl derivative 11 in high yield. Acetylation of 9 by refluxing in acetic acid, afforded acetic acid N -(2-(7-hydroxy-2-oxo-2H-chromen-4-yl)-acetyl)-hydrazide 12 in good yield. Compound 13 was also obtained by refluxing 9 with 3-(2-bromoacetyl)-4-hydroxy-2H-chromen-2-one in ethanol. Reaction of compound 9 with phenyl isothiocyanate in ethanol at room temperature gave 4-phenyl-1 - (7-hydroxy-2-oxo-2 H-chromen-4-acetyl- )thiosemicarbazide 14. 

CAS 93-35-6 EINECS/ELINCS 202-240-3 Synonyms 2H-1-Benzopyran-2-one, 7-hydroxy- Coumarin, 7-hydroxy Hydrangin 7-Hydroxy-2H-1-benzopyran-2-one 7-Hydroxy-chromen-2-one... 

Fouaissier and Chesneau reported that an cosine dye and ketocoumarin in the presence of an amine, acetone and iodonium salts initiate photocuring with light greater in wave length that 400 nm., The ketocoumarin (7-diethylamino-3,3 -oxydo-2H-chromen-2-one) was found by them to be a very useful additive to photo curable formulations, either in free-radical or in ionic curing processes illustrated as follows... 

Other Names Coumarin, 7-hydroxy-4-methyl- Umbelliferone, 4-methyl- P-Methylumbelliferone 4-MU 4-Methyl-7-hydroxycoumarin 4-MethylumbelUferone 7-Hydroxy-4-methyl-2-chrome-none 7-Hydroxy-4-methyl-2-oxo-3-chromene 7-Hydroxy-4-methyl-2H-l-benzopyran-2-one 7-Hydroxy-4-methyl-2H-chromen-2-one 7-Hydroxy-4-melhylcoumarin BilcoUc Bilicante Bili-ton H Cantabilin Cantabiline Cholestil Cholonerton Cholspasmin Coumarin 4 Coumarin 456 Cumarote C Eurogale Himecol Hymecromone Imecromone LM 94 Medilla Mendiaxon NSC 19026 NSC 9408 Omega 127 Pilot 447 CA Index Name 2H-l-Benzopyran-2-one, 7-hydroxy-4-methyl-CAS Registry Number 90-33-5 Merck Index Number 4854 Chemical Structure... 

Hydroxy-4,5-dimethyl-2H-chromen-2-one (3d) Solid, mp 243-245 °C reaction time 50 sec yield 92%... 

Ronad, P Dharbamalla, S. Hunshal, R. Maddi, V. Synthesis of novel substituted 7-(benzylideneamino)-4-methyl-2H-chromen-2-one derivatives as anti-inflammatory and analgesic agents. Arch. Pharm. 2008,341, 696-700. 

G.16) 2//-l-Benzopyran-2-one, 7-hydroxy-6-methoxy-, 7-hydroxy-6-methoxy-2W-chromen-2-one. 7-hydroxy-6-methoxy-2H-l-benzopyran-2-one, 7-hydroxy-6-methoxycoumarin, scopoletin, 0-methylesculetin 92-61-5 ... 

However, when 36 was heated with a-amino heterocycles or with cyclic 1,3-dicarbonyl or potential 1,3-dicarbonyl compounds, 3-heteroarylp)rr-azol derivatives were obtained. In this manner 36 afforded, when heated with 2-aminopyridine and 3-amino-lH-pyrazol in acetic acid under reflux for 2 h and 5 h, respectively, 3-(5-ethoxy-l-phenyl-lH-pyrazol-3-yl)-4H-pyrido[l,2-fl]pyrimid-4-one (38) and 6-(5-ethoxy-l-phenyl-lH-p5rrazol-3-yl)pyrazolo[l,5-fl]pyrimid-7(lH)-one (39) in 70% and 77% 5deld, respectively. Similarly, 36 afforded with cyclicjS-dicarbonyl compounds, such as 4-hydroxy-6-methyl-2H-pyran-2-one and 5,5-dimethylcyclohexane-l,3-dione by heating in acetic acid for 4 h and 8 h, respectively, the corresponding 3-(5-ethoxy-l-phenyl-lH-pyrazol-3-yl)-7-methyl-2H,5H-pyrano[4,3- 7]pyran-2,5-dione (40) and 3-(5-ethoxy-l-phenyl-IH-pyrazol-3-yl)-7,7-dimethyl-7,8-dihydro-2H-chromene-2,5-dione (41) in 26% and 82% yield, respectively (Scheme 15). 

Roltlerin. I- 6-[(3-Acetyl-2,4,6-trihydroxy-S-methylphenyl)methyl]-5,7-dihydroxy-2t 2-dimethyl-2H-l-benzopyran-8-yl]-3-phenyt-2-propen-I-one 5,7-dihydroxy -2,2 di methyl -6 -(2,4,6 -t rihydroxy - 3 -methyl - 5 -acetylbenz-yl)-8-dnnamoyl-l,2-chromene mallotoxin. C H O, mol wt 516.52. C 69.75%, H 5.46%, O 24.78%, Most important and powerful toxic component of Kamala, q.v. lsoln from Kamala or Mallotus philippinensis (Lam.) Muell.-Arg. (Rott-fera tlnctorla Roxb.), Euphorbiaceae Telle. Arch. Pharm. 

A remarkably simple approach to racemic pterocarpin is indicated by a two-step synthesis (ref.110) in which 7-methoxy-2H-chromen, readily formed by dehydration of the reduction product of 7-methoxychroman-4-one, was reacted in the presence of lithium chloropalladite with 2-chloromercuri-4,5-methylenedioxyphenol. This reactant was itself obtained from 3,4-methylenedioxyphenol and mercuric acetate followed by treatment with sodium chloride. The process is illustrated in Scheme 32. 

By contrast, the reaction of resorcinol with mesityl oxide (2-methylpent-2-ene-one) in the presence of barium hydrate at 150-170°C in vacuo (165-170mm Hg) with azeotropic removal of water during 5 hours has been claimed to afford a 34% yield of 2,2,4-trimethyl-5-hydroxy-2H-chromene rather than the 7-hydroxy isomer (ref.116). 

S Synonyms. 7-Hydroxy-4-methyl-2H-l-benzopyran-2-one Hymecromone Imecromone 7-Hydroxy-4-methyl-2-oxo-3-chromene 4-Methylumbelliferone P-Methylum-belliferone ... 

Condensation of 3-(2-amino-4-thiazolyl)comnarin 91 with a-acetyl-y-butyrolactone in a mixture of polyphosphoric acid and POCI3 afforded thiazolo[3,2-a]pyrimidin-5-one 92, while condensation of 91 with P-keto esters gave 7-methyl-3 -(2-oxo-2H-chromen-3 -yl)-5 H-[ 1,3]thiazolo [3,2 -a]pyrimidin-5 -ones 93(Scheme 42). Reaction between 91 and diethyl 2-(methoxymethylene)malonate imder solvent-free conditions yielded 3-(2-oxo-2H-chromen-3-yl)-5-oxo-5H[l,3]thiazolo[3,2-a]pyrimidine-6-carboxylate 94 [67],... 

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