Aluminum(III) Chloride → HCID 136053481, compound

HRID 1381090Notes

Reaction equation

HRID 1381090 reaction equation
[CH3:1][C:2]1[O:3][C:4]([CH3:21])=[C:5]2[C:14](=[O:15])[C:13]3[C:8](=[C:9]([O:18]C)[CH:10]=[CH:11][C:12]=3[O:16]C)[C:7](=[O:20])[C:6]=12.[Cl-].[Al+3].[Cl-].[Cl-]>ClCCl>[CH3:21][C:4]1[O:3][C:2]([CH3:1])=[C:6]2[C:7](=[O:20])[C:8]3[C:13](=[C:12]([OH:16])[CH:11]=[CH:10][C:9]=3[OH:18])[C:14](=[O:15])[C:5]=12

Participants

4

Reactant 2

HCID 6451240Aluminum(III) ChlorideHCID 13710979HCID 13710979, compound

Product 1

HCID 136053481HCID 136053481, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

In accordance with the Flowchart I, 2,5-dimethyl furan (formula 12) is reacted in step A with CH3CO2 (--C≡C--)CO2CH3 (formula 13) to produce 1,4-dimethyl-7-oxabicyclo[2,2,1]octa-2,5-diene-2,3-dicarboxylic acid, dimethyl ester (formula 14). The latter is catalytically hydrogenated in ethyl acetate (step B) to produce 2,5-dimethyl-3,4-furandicarboxylic acid, dimethyl ester (formula 15), which is treated with aqueous base at reflux for several hours and then acidified to produce 2,5-dimethyl-3,4-furandicarboxylic acid (formula 16). The latter is then treated (Step D) with thionyl chloride at reflux to produce 2,5-dimethyl-3,4-furandicarbonyl chloride (formula 17), which is then reacted in Step E with 1,4-dimethoxybenzene and anhydrous stannic chloride in dichloromethane at 0°-5° C. for several hours, and then acidified under an inert atmosphere. The product is extracted at 40°-45° C. in chloroform and chromatographed, to produce 1,3-dimethyl-5,8-dimethoxynaphtho[2,3-c]furan-4,9-dione (formula 18). Such dione (18) is then treated in step F with anhydrous aluminum chloride in dichloromethane at 40°-45° C. for several hours, acidified and extracted at 50°-55° C. into chloroform and crystallized from glacial acetic acid, to produce 1,3-dimethyl-5,8-dihydroxynaphtho[2,3-c]furan-4,9-dione (formula 19). The latter is then treated in step G with lead tetraacetate in acetic acid and extracted with dichloromethane, to produce 1,3-dimethylnaphtho-[2,3-c]furan-4,5,8,9-tetrone (formula 20).

Workup

  1. extractionextracted at 50°-55° C. into chloroform
  2. customcrystallized from glacial acetic acid

Sources & evidence

ORD record
ord-b3c0c4ba506f4bc49df33bb584a2d27b
Source dataset
uspto-grants-1986_04
Patent number
US04585760

Reaction notes

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