1.3- dihydro-2-benzofuran

Atractyligenin-2-O-P-D-glucoside Sd 220 A083 Avenasterol, 5-dehydro Sd Ai07 Benzaldehyde, 3-4-dihydroxy Sd Ai22 Benzaldehyde Sd Hu aosz Benzofuran, 2-3-dihydro Sd Hu aosz... 

Benzofuranic acids iraws-meranzinic acid (56).162 Euparinoid benzofurans the important class of euparinoids (extracts of plants of the Compositae family), contains benzofurans, dihydro-benzofurans, and also includes compounds with a hydronaphthofuran ring. We mention euparin (the earliest known) (5-acetyl-6-hydroxy-2-isopropenylbenzofuran) (57, R6=OH, R =H) 163 166, dehydro-tremetone (5-acetyl-2-isopropenylbenzofuran) (57, R6—R —H),167,168... 

Fluorophenyl)-l ]-hydroxy-2,3,4,1 ]-tetrahydro-6/7-pyrimido[],2-Z)]-isoquinolin-6-one was obtained in the reaction of l-(4-fluorophenyl)-3-oxo-],3-dihydro-2-benzofuran-l-carboxamide and 1,3-diaminopropane in boiling toluene (01BMCL339). 

The furan ring can be made to polymerize through one or both of its double bonds and the polymers obtained will therefore have dihydro- and tetrahydrofuran rings in their backbone. This situation occurs when furan, the alkylfurans, benzofuran and some dihydrofurans are treated with suitable initiators and is discussed in the first section of this chapter. 

Bromomethyl-3,4-dibromo-3,4-dihydrocoumarin 1 (Fig. 11.4) and its chloro-methylated analogue 2b rapidly and progressively inactivate a-chymotrypsin and also the activities of a series of trypsin-like proteases. A benzyl substituent characteristic of good substrates of a-chymotrypsin was introduced at the 3-position to make inhibition more selective. This substituted dihydrocoumarin 3 irreversibly inhibited a-chymotrypsin and other proteases. These functionalized six-membered aromatic lactones, and their five- and seven-membered counterparts, 3//-benzofuran-2-ones 2a26 and 4,5-dihydro-3//-benzo[b]oxepin-2-ones 2c,27 were the first efficient suicide inhibitors of serine proteases. Their postulated mechanism of action is shown in Scheme 11.2. 

This review of furan chemistry is meant to continue the earlier survey by Bosshard and Eugster1 and concentrates upon the period 1968 to the end of 1979. Like the earlier review, this one is limited to the chemistry of the monocyclic furan nucleus and does not deal, except incidentally, with fused rings such as benzofuran or its quinones. Nor does it deal in detail with dihydro- or tetrahydrofurans, nor with compounds like furylpyridine that contain some other heterocyclic nucleus as well. Some butenolides and tetronic acids are admitted to consideration since they are the carbonyl equivalents of hydroxyfurans regarded as enols, but side-chain reactions are wholly excluded unless the furan nucleus clearly affects them in some important way. 

In a similar way, benzofurans and N-methylpyrrole afford 2,3-dimethoxylated derivatives (Scheme 97) [160]and2,5-tetra-methoxy-2,5-dihydro-AI-methylpyrrole, respectively (Scheme 98) [57, 161,162]. 

Synonyms AI3-04869 AIDS-189608 AIDS-189615 AIDS-189616 AIDS-189618 AIDS-169619 AIDS-169620 AIDS-169621 Araldite HT 901 1,2-Benzenedicarboxylic acid anhydride 2-Benzofuran-l,3-dione BRN 0118515 CCRIS 519 1,3-Dioxophthalan EINECS 201-607-5 ESEN 1,3-Dihydro-1,3-dioxoisobenzofuran HT 901 Isobenzofuran-l,3-dione 1,3-Iso-benzofurandione NCI-C03601 NSC 10431 PAN Phthalandione 1,3-Phthalandione Phthalic acid anhydride Phthalanhydride RCRA waste number U190 Retarder AK Retarder ESEN Retarder PD Retarder PX Sconoc 7 TGL 6525 UN 2214 Vulcalent B Vulcalent B/C Wiltrol P. 

Reductive detelluration of cyclic telluroethers (typical procedure) To a solution of 2,3-diliydro-2-[(phenylteUuro)methyl]benzofuran (0.338 g, 1 mmol) in toluene (6 ml.) is injected TBTH (0.67 ml, 2.5 mmol) at room temperamre, and the resulting solution is stirred under reflux for 1 h. The solution is evaporated under vacuum and the residual yellowish oil subjected to Si02 column chromatography (eluting with benzene/hexane, 3 1) to give pure 2,3-dihydro-2-methylbenzofuran as a colourless oil (0.128 g (95%) b.p. 93-94°C/23 torr). 

Benzofurans are oxidised at a carbon anode in methanol at - 10 °C to the 2,3-dihydro-2,3-dimethoxybenzofuran [190]. 

Polymerization of 1 -benzofuran with an optically active initiator gives the optically active polymer, poly[(27 ,35)-2,3-dihydro-l-benzofuran-2,3-diyl], containing predominantly one type of stereorepeating unit. 

The carbamates formed from 2-hydroxychalcones and alkyl or aryl isocyanates readily cyclize to 3,4-dihydro-l,3-benzoxazin-2-one derivatives <1996CHEC-II(6)301>. When hydroxychalcones 318 with a benzofuran moiety were heated under reflux with phenyl isocyanate in benzene in the presence of a catalytic amount of potassium hydroxide, l,3-benzoxazin-2-one derivatives 320 were formed through the intermediate open-chain carbamates 319 (Scheme 61) <2006JHC437>. 

Foo, L.Y. et al., Proanthocyanidins from Lotuspedunculatus, Phytochemistry, 45, 1689, 1997. Steynberg, P.J. et al.. Acid-catalyzed rearrangements of flavan-4-phloroglucinol derivatives to novel 6-hydroxyphenyl-6a,llb-dihydro-677-[l]benzofuro[2,3-c]chromenes and hydroxyphenyl-3,2 -spirobi[dihydro[l]benzofurans], J. Chem. Soc., Perkin Trans. 1, 2395, 1997. 

In Gegenwart von sek. Aminen (z. B. + -tp-Ephedrinen) reagiert 3-Methoxycarbonyl-1-oxo-1,3-dihydro-2-benzofuran mit 2-Nitro-1-phenyl-ethen zu l-Methoxycarbonyl-l-(2-ni-tro-l-phenyl-ethyl)-3-oxo-l, 3-dihydro-2-benzofuran ( 100%) ... 

Unter fast gleichen Bedingungen erhalt man aus 2-Allyl-3-oxo-l-pyrrolidino-cyclohexen cin mercuriertes Benzofuran-Derivat, dessen Reduktion mit Natriumboranat 2-Methyl-4-pyrrolidino-2,3-dihydro-l-benzofuran ergibt2 ... 

Methyl-o-benzyloxyphenylglyoxylate (32) cyclizes on irradiation to give an isomeric mixture of 2-phenyl-3-carboxymethyl-3-hydroxyl-2,3-dihydro-benzofurans (33), apparently by an internal hydrogen abstraction-cyclization mechanism.103 This abstraction must take place through a seven-membered... 

F. R., Astruc-Diaz, F., Thompson, . M., Cavasotto, C. N., Naguib, M. (2009) 2,3-Dihydro-1-benzofuran derivatives as a series of potent selective cannabinoid receptor 2 agonists design, synthesis, and binding mode prediction through ligand-steered modeling. ChemMedChem 4, 1615-1629. 

Pesticidal carbamates with 2,3-dihydrobenzofuran structures carbo-furan or NIA-9242 is methyl 2,3-dihydro-2,2-dimethyl-7-benzofuranyl-carbamate (14) NIA 10559 (15) is its 4-chloro, and NIA 10586 (16) its 4-methyl derivative. Benzofuran itself, 2,3-dibromobenzofuran and 2,3-dihydro-3-oxobenzofuran and their derivatives have very low or zero activity.26... 

Dihydro-2-hydroxy-6-methyl-3-methylenebenzofuran,42,43 a simple natural benzofuran, has nematocidal properties. 

In the 3-phenyl-2(3 )-benzofuranone series, we find a long-known spasmolytic compound, 3-(2-diethylamino)ethyl-3-phenyl-2(3H)-benzo-furanone30ft,6Ba,b (Amolanone), which also has analgesic properties. A novel compoimd, 2-(l-succinyloxy)ethyl-3-methyl-5-(2-oxo-2,5-dihydro-4-furyl)benzofuran or Benfurodil69 (25) (clinical name Eudilat), is a vasodilator and cardiotonic. 

Although alkylbenzofuran derivatives (e.g., 2-methyl-2,3-dihydro-benzofuran) have no vitamin F activity,88 they seem to show some regulating activity on plant growth.89 The 2,2-dimethyl-2,3-dihydro-benzofuran ring is an effective toxophore.90... 

The unsaturated compound first formed from the o-alkylphenol then undergoes ring closure. Some phenoxylated alcohols, looked upon as forerunners of compounds (104), such as l-phenoxy-2-propanol, also undergo ring closure with dehydrogenation (400°, A1203) to benzofuran derivatives, viz., to 2-methylbenzofuran (mixed with the 2,3-dihydro derivative).290... 

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