Method for producing 2-acetyl-4h,9h-naphtho[2,3-b]furan-4,9-dione

Abstract

The invention addresses the problem of providing a method for producing 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione that is suited to industrial production. The invention provides a method for producing 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione by reacting 3-bromo-3-buten-2-one and 2-hydroxy-1,4-naphthoquinone in the presence of a solvent, then obtaining crystals of 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione by adding an alcohol-based solvent and/or water to the reaction system, and treating the crystals by using a specific adsorbent in the presence of a solvent.

1 - 39 . (canceled) 
     
     
         40 . A compound of 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione which is obtained by a process comprising the following step (d):
 (d) dissolving 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione in a non-alcohol-based solvent C, followed by adding an adsorbent to purify the 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione.   
     
     
         41 . The compound according to  claim 40 , further comprising the following step (e) after the step (d):
 (e) removing the adsorbent used in the step (d) and evaporating the non-alcohol-based solvent C.   
     
     
         42 . The compound according to  claim 41 , further comprising the following step (f) after the step (e):
 (f) crystallizing 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione obtained in the step (e) by adding at least one crystallization solvent D selected from the group consisting of a hydrocarbon-based solvent, an alcohol-based solvent, an acid-based solvent, an ester-based solvent, an ether-based solvent, and water, to obtain 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione.   
     
     
         43 . The compound according to  claim 42 , further comprising the following step (g) after the step (f):
 (g) slurrying 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione obtained in the step (f) with ethyl acetate to form a crystal of 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione.   
     
     
         44 . The compound according to  claim 40 , wherein the non-alcohol-based solvent C used in the step (d) is at least one selected from the group consisting of an ether-based solvent, an amide-based solvent, a ketone-based solvent, a halogen-based solvent, a sulfoxide-based solvent, an ester-based solvent, a hydrocarbon-based solvent, and a nitrile-based solvent. 
     
     
         45 . The compound according to  claim 40 , wherein the non-alcohol-based solvent C used in the step (d) is at least one selected from the group consisting of chloroform, dichloromethane, carbon tetrachloride, monochlorobenzene, N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, acetonitrile, propionitrile, dimethyl sulfoxide, diethyl sulfoxide, diisopropyl ether, tert-butyl methyl ether, cyclopentyl ethyl ether, cyclopentyl methyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, anisole, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, toluene, xylene, acetone, methyl ethyl ketone, and methyl isobutyl ketone. 
     
     
         46 . The compound according to  claim 40 , wherein the non-alcohol-based solvent C used in the step (d) is at least one selected from the group consisting of N,N-dimethylacetamide, N,N-dimethylformamide, anisole, ethyl acetate, propyl acetate, and butyl acetate. 
     
     
         47 . The compound according to  claim 40 , wherein the non-alcohol-based solvent C used in the step (d) is anisole. 
     
     
         48 . The compound according to  claim 40 , wherein the adsorbent used in the step (d) is at least one selected from the group consisting of activated alumina, zeolite, activated carbon, and silica gel. 
     
     
         49 . The compound according to  claim 40 , wherein the adsorbent used in the step (d) is silica gel. 
     
     
         50 . The compound according to  claim 40 , wherein the adsorbent used in the step (d) is a 0.01 to 0.3-fold amount in a weight ratio to 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione. 
     
     
         51 . The compound according to  claim 50 , wherein the adsorbent used in the step (d) is a 0.02 to 0.2-fold amount in a weight ratio to 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione. 
     
     
         52 . The compound according to  claim 42 , wherein the crystallization solvent D used in the step (f) is at least one selected from the group consisting of n-heptane, xylene, n-butanol, isobutyl acetate, toluene, cyclohexane, acetic acid, methanol, ethanol, 1-propanol, 2-propanol, n-butyl alcohol, isobutyl alcohol, and water. 
     
     
         53 . The compound according to  claim 42 , wherein the crystallization solvent D used in the step (f) comprises n-heptane. 
     
     
         54 . The compound according to  claim 42 , wherein the crystallization solvent D used in the step (f) comprises xylene. 
     
     
         55 . The compound according to  claim 42 , wherein the crystallization solvent D used in the step (f) comprises n-butanol. 
     
     
         56 . The compound according to  claim 42 , wherein the crystallization solvent D used in the step (f) comprises isobutyl acetate. 
     
     
         57 . The compound according to  claim 40 , wherein the purification temperature is 30° C. to 100° C. 
     
     
         58 . The compound according to  claim 40 , wherein the purification temperature is 50° C. to 90° C. 
     
     
         59 . The compound according to  claim 40 , wherein the purity of the compound is not less than 99.95%. 
     
     
         60 . A medicament comprising the compound of  claim 40 .