Water → HCID 20283281, compound

HRID 647644Notes

Reaction equation

HRID 647644 reaction equation
[OH:1][C:2]1([C:16]([O:18][CH3:19])=[O:17])[CH2:11][CH2:10][C:9]2[C:4](=[C:5]([O:14][CH3:15])[CH:6]=[CH:7][C:8]=2[O:12][CH3:13])[CH2:3]1.[C:20](OC(=O)C)(=[O:22])[CH3:21].O>N1C=CC=CC=1.CN(C)C1C=CN=CC=1>[C:20]([O:1][C:2]1([C:16]([O:18][CH3:19])=[O:17])[CH2:11][CH2:10][C:9]2[C:4](=[C:5]([O:14][CH3:15])[CH:6]=[CH:7][C:8]=2[O:12][CH3:13])[CH2:3]1)(=[O:22])[CH3:21]

Participants

6

Reactant 3

HCID 962WaterHCID 7918Acetic AnhydrideHCID 13042105HCID 13042105, compound

Product 1

HCID 20283281HCID 20283281, compoundYield 96.5%

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 1049PyridineSolvent

Conditions

Temperature
0 °C

Procedure

5.0 g of methyl rac-1,2,3,4-tetrahydro-2-hydroxy-5,8-dimethoxynaphthalene-2-carboxylate were dissolved in 50 ml of pyridine. The solution was cooled to 0° C. and 10 ml of acetic anhydride and 150 mg of 4-dimethylaminopyridine were added. After standing at 0° C. for 24 hours, the mixture was poured into 250 ml of water. The mixture obtained was extracted with three 100 ml portions of ethyl acetate and the combined ethyl acetate extracts were washed with 2-N hydrochloric acid until the washings were acidic, then with 200 ml of water, 200 ml of dilute aqueous potassium hydrogen carbonate and 200 ml of brine. After drying, the solvent was evaporated to give a white crystalline residue. Recrystallisation from diethyl ether gave 5.6 g (96.5%) of methyl rac-2-acetoxy-1,2,3,4-tetrahydro-5,8-dimethoxynaphthalene-2-carboxylate in the form of colourless crystals of melting point 155.5°-156° C.

Workup

  1. customThe mixture obtained
  2. extractionwas extracted with three 100 ml portions of ethyl acetate
  3. washthe combined ethyl acetate extracts were washed with 2-N hydrochloric acid until the washings
  4. customAfter drying
  5. customthe solvent was evaporated
  6. customto give a white crystalline residue
  7. customRecrystallisation from diethyl ether

Sources & evidence

ORD record
ord-190d5936acc14684ac03ab3884b80668
Source dataset
uspto-grants-1983_10
Patent number
US04409391

Reaction notes

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