Coumarinic anhydride

Synonyms 1,2-Benzopyrone 5,6-benzo-2-pyrone benzo-a-pyrone cis-ortho-co x-marinic acid lactone coumarinic anhydride ort/jo-hydroxyciimamic acid lactone... 

SYNS 2H-1-BENZOPYRAN-2-ONE 1,2-BENZO-PYRONE cis-o-COUiMARINIC ACID LACTONE COUMARINIC ANHYDRIDE o-HYDROXYCINNAMIC ACID LACTONE o-HYDROXYZIMTSAEURE-LACTON (GERMAN) NCI-C60297 2-OXO-l,2-BENZOPYRAN RATTEX TONKA BE.YN CAMPHOR... 

SYNS FEMA No. 2690 6-MC 6-METHYD2H-1-BENZOPYRAN-2-ONE 6-METHYLBENZOPYRONE 6-METHYDL2-BENZOPYRONE 6-METHYD COUMARINIC ANHYDRIDE NCI-C55812 TONCARINE... 

Synonyms Coumarin 2f-f-l-Benzopyran-2-one 1,2-Benzopyrone cfs-o-Coumaric acid lactone Coumarinic anhydride 2-Oxo-l,2-benzopyran Tonka bean camphor note coumadin and warfarin are not synonyms for coumarin) Chemical/Pharmaceutical/Other Class Benzo-a-pyrone... 

CoUknarin, 2H-1 -Renzopyran-2-one 1,2-benzopyrene cis-o-coumarinic acid lactone cumarin coumarinic anhydride tonka bean camphor. C4H602. mol wt 146.14. C 73-96%, H 4.14%, O 21-90%. In tonka beans, lavender oil, woodruff (Asperuta species), in sweet clover (MeUlotus). Crystal and molecular structure Chem. Commun.. Univ. 

Beilstein Handbook Reference) AI3-00753 Benzo-a-pyrone BRN 0383644 Caswell No. 259C CCRIS 181 Cinnamic acid, o-hydroxy-, 8-lKtone ois-o-Coumaric acid anhydride Coumarin cis-o-Coumarinic acid lactone Coumarinic anhydride Coumarinic lactone Cumarin EINECS 202-086-7 EPA Pesticide Chemical Code 127301 HSDB 1623 o-Hydroxycinnamic lactone 0-Hydroxyzimtsaure-lacton Kumarin NCI C07103 NSC 8774 Rattex Tonka bean camphor. Used in pharmaceuticals as a flavorant. Crystals mpo 71" bp = 301.7 d O = 0.936 Xm = 273, 311 nm (e = 11200, 6710, MeOH) moderately soluble in H2O, EtOH, more soluble in EtzO, CHCI3, C5H5N. Alfa Aesar Rhodia Inc. Rhodia Organique Fine Ltd. 

Synonyms. 1, 2-Benzopyrone 2H-l-Benzopyran-2-one cis-o-Coumarinic acid lactone Cumarin Coumarinic anhydride Tonka bean Camphor ... 

Coumarin (coumarinic anhydride) and drivatives are added as a fragrance to topical preparations. Allergic contact dermatitis from coumarin derivatives was seen in a patient who had applied Jecovitol ointment to a foot ulcer (Van Ketel 1973). The synthetic 6-methylcoumarin has caused allergic photocontact dermatitis (Kaidby and Kligman 1978). 

Synonyms 1-Benzopyran-2-one 2H-1-Benzopyran-2-one 2H-1-Benzopyran, 2-oxo- Benzopyrone 1,2-Benzopyrone Benzo-a-pyrone Chromen-2-one Cinnamic acid, o-hydroxy-, 5-lactone Coumaric acid cis-o-Coumaric acid lactone cis-o-Coumarinic acid lactone Coumarinic anhydride Cumarin o-Hydroxycinnamic acid lactone o-Hydroxycinnamic acid 5-lactone o-Hydroxycinnamic lactone 2-Oxo-1,2-benzopyran 2-Propenoic acid, 3-(2-hydroxyphenyl)-5-lactone Tonka bean camphor... 

Coumarin, 3(3-(4-biphenylyl)-1,2,3,4-tetrahydro-1-naphthyl)-4-hydroxy-. See Difenacoum, Coumarin, 7-diethylamino-4-methyl-. See 7-Diethylamino-4-methyl coumarin Coumarin, 7-hydroxy. See 7-Hydroxycoumarin Coumarin, 4-hydroxy-3-(1,2,3,4-tetrahydro-1-naphthyl)-. See Coumatetralyl cis-o-Coumarinic acid lactone Coumarinic anhydride. See Coumarin Coumarone. SeeCumarone Coumarone/indene copolymer. See Coumarone/indene resin Coumarone/indene resin CAS 35343-70-5 63393-89-5 Synonyms Coumarone/indene copolymer Coumarone resin Indene/coumarone resin Poly (coumarone-co-indene) Polyindene resin Classification Thermosetting resin Properties Brn. solid soft and sticky at R.T. hardens on heating to solid sol. in hydrocarbon soivs., pyridine, acetone, carbon disulfide, CCU insol. in water, alcohol dens. 1.140 soften, pt. 

Other Names Coumarin 1,2-Benzopyrone 2-Propenoic acid, 3-(2-hydroxyphenyl)-, 8-lactone 5,6-Benzo-2-pyrone Benzo-a-pyrone Coumarinic anhydride NSC 8774 Rattex Tonka bean camphor cis-o-Coumarinic acid lactone o-Hydroxycinnamic acid lactone CA Index Name 2H-l-Benzopyran-2-one CAS Registry Number 91-64-5 Merck Index Number 2562 Chemical Structure... 

Coumarin is usually prepared by heating salicylaldehyde with acetic anhydride and sodium acetate (i.e., the Perkin cinnamic acid synthesis, p. 23 6), whereby the 0" hydroxy-cinnamic acid (I) undergoes cyclisation to coumarin. Coumarins having substituents in the benzene ring can often be similarly prepared. 

Basic catalysts other than alkali acetates have been employed in the Perkin reaction thus salicylaldehyde condenses with acetic anhydride in the presence of triethylamine to yield coumarin (tlie lactone of the cis form of o-hydroxy-cinnamio acid) together with some of the acetyl derivative of the trans form (o-acetoxycoumaric acid) ... 

Coumarin. In a 250 ml. round-bottomed flask, provided with a small reflux condenser and a calcium chloride drying tube at the top, place 2 1 g, of salicylaldehyde, 2 0 ml. of anhydrous triethylamine and 5 0 ml. of acetic anhydride, and reflux the mixture gently for 12 hours. Steam distil the mixture from the reaction flask and discard the distillate. Render the residue in the flask basic to litmus with solid sodium bicarbonate, cool, filter the precipitated crude coumarin at the pump and wash it with a little cold water. Acidify the filtrate to Congo red with... 

Perkin Reaction. A product of significant commercial importance, coumarin [91-64-5] is made by the reaction of sahcylaldehyde with acetic anhydride and sodium acetate, a Perkin reaction (61). 

The conversion of c>-hydroxyaryl ketones la to chromones 2a and/or coumarins 3a with aliphatic acid anhydrides in the presence of the sodium or potassium salt of the corresponding acid and the reaction between lb and aromatic acid anhydrides and the salt of the corresponding acid to form flavones 2b (Allan-Robinson) is called the Kostanecki-Robinson (K-R) reaction. ... 

Coumarin formation proceeds via an intramolecular attack by enol ester 9 on the ketone to give 10. Dehydration of 10 then affords coumarin 11. It has been observed that coumarins are favored when higher order homologs of acetic anhydride and their corresponding salts such as propionic anhydride/sodium propionate and butyric anhydride/ sodium butyrate are used. 

Sen and Kakaji synthesized a series of 4-butyrylnaphthocoumarins 48 from l-butyryl-2-naphthols 49 using acetic anhydride and two homolog anhydrides in excellent yields. They also showed that l-propionyl-2-naphthols and l-acetyl-2-naphthols could be converted to their corresponding coumarins using the same three anhydrides. However, l-acetyl-2-naphthol in the presence of acetic anhydride and sodium acetate gave a chromone not a coumarin. 

In addition to their work on naphthocoumarins, Sen and Kakaji showed that 4-t-butyl-2-hydroxyphenones 50 gave exclusively coumarins 51 when treated with various anhydrides in the presence of their corresponding sodium carboxylates. They saw similar results with 4-t-amyl-2-hydroxyphenones. 

Couviarin, C HgOj, is, chemically, the 8-lactone of coumarinic acid (o-oxycinnamic anhydride), of the constitution—... 

Coumarin was first produced synthetically by Perkin. He made it by heating salicylic aldehyde, CgH (OH)i(COH), acetic anhydride, and sodium acetate. The whole solidifies to a crystalline mass, from which, on treatment with water, an oil separates containing coumarin and aceto-coumaric acid. This acid on heating is decomposed into acetic acid and coumarin, so that the product of distillation is principally coumarin. Perkin s synthesis proceeds according to the following equation —... 

The synthesis of Coumarin derivatives can be made cleaner using zeolite H-BEA and even cationic ion-exchange resin like Amberlyst-15 works. Reactions of resorcinol with acrylic/methacrylic acid, maleic anhydride and esters have been studied (Gunnewegh et al., 1996). 

One-pot conversions of 2-hydroxy(acylbenzenes) with anhydrides or acid chlorides to produce coumarins [52-54] and flavones [54-58] under mild liquiddiquid or solidtliquid two-phase conditions via a Baker-Venkataraman type reaction (Scheme 6.19) are catalysed by quaternary ammonium salts. 3-Substituted coumarins are produced from salicylaldehyde and malonodinitrile, or substituted acetonitriles, in high yield (>85%) in a one-pot catalysed sequential aldol-type reaction and cycliza-tion in the absence of an added organic solvent [59]. When 2 -hydroxychalcones are reduced under catalytic two-phase conditions with sodium borohydride, 2,4-cis-flavan-4-ols are produced [60] (see Section 11.3). 

Production. Coumarin is currently produced by Perkin synthesis from salicyl-aldehyde. In the presence of sodium acetate, salicylaldehyde reacts with acetic anhydride to produce coumarin and acetic acid. The reaction is carried out in the liquid phase at elevated temperature. 

The synthesis consists of heating a mixture of the o-hydroxybenzaldehyde with the sodium salt and anhydride of a carboxylic acid, usually acetic acid. Generally, a temperature in the range 150-200 °C is required and a prolonged reaction time is often necessary. A 1 2 molar ratio of aldehyde to anhydride gives optimum yields of coumarin (Scheme 124). 

Phenylcoumarin is formed when phenylacetylsalicylaldehyde (392 R = Ph) is heated with sodium acetate or phenylacetate, an intramolecular cyclization being followed by elimination (Scheme 126). However, acetylsalicylaldehyde gives only a trace of coumarin when heated with sodium acetate under a variety of conditions, indicating that an intramolecular reaction does not take place. Addition of acetic anhydride results in the... 

Low yields of coumarin-4-carboxylic acids result from the reaction of benzofuran-2,3-diones with acetic anhydride in the presence of a trace of pyridine (70BCJ1590). 

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