Imidazole → Methyl 6-tert-butyldimethylsilyloxy-2-naphthoate

HRID 725698Notes

Reaction equation

HRID 725698 reaction equation
[OH:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[CH:8]=[C:7]([C:12]([O:14][CH3:15])=[O:13])[CH:6]=[CH:5]2.[C:16]([Si:20](Cl)([CH3:22])[CH3:21])([CH3:19])([CH3:18])[CH3:17].N1C=CN=C1.C([O-])([O-])=O.[Na+].[Na+]>CN(C=O)C.C(OCC)(=O)C.CCCCCC>[Si:20]([O:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[CH:8]=[C:7]([C:12]([O:14][CH3:15])=[O:13])[CH:6]=[CH:5]2)([C:16]([CH3:19])([CH3:18])[CH3:17])([CH3:22])[CH3:21]

Participants

7

Reactant 4

HCID 795ImidazoleHCID 10340Sodium CarbonateHCID 28928tert-Butyldimethylsilyl chlorideHCID 390995Methyl 6-hydroxy-2-naphthoate

Product 1

HCID 14645564Methyl 6-tert-butyldimethylsilyloxy-2-naphthoateYield 88.5%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolvent2×HCID 21226206Ethyl acetate hexaneSolvent

Procedure

A 10 mL round bottom flask fitted with magnetic stirrer and pressure-equalizing dropping funnel was charged with 3 mL of DMF which had been dried by vacuum distillation from CaH2. Methyl 6-hydroxy-2-naphthoate (1.01 g, 5 mmol) and t-butyldimethyl silyl chloride (0.83 g, 5.5 mmol) were added and the atmosphere replaced with nitrogen. A solution of imidazole (0.75 g, 11 mmol) in 3 mL of dry DMF was added via the dropping funnel over 15 minutes, and stirring continued for 4 hours. TLC analysis (SiO2, 5% ethyl acetate/hexane) showed clean conversion to a new material. The solution was poured into 50 mL of 1% aq. Na2CO3 solution and extracted with 3-35 mL portions of pentane. The combined pentane solutions were washed with 25 mL of water, 25 mL of brine and dried over MgSO4. Evaporation of the pentane yielded 1.45 g of slightly yellow solid. Purification by column chromatography on silica using 5% (V/V) ethyl acetate/hexane as eluent afforded 1.4 g (88%) of white solid after recrystallization from pentane: mp 72°-72.5° C.; 1H NMR delta 0.266 (s, 6H), 1.022 (s, 9H), 3.958 (s, 3H), 7.19-8.53 (m, 6H); 13C NMR delta -4.35, 18.23, 25.64, 52,03, 114.74, 122.87, 125.38, 125.62, 126.75, 128.16, 130.87, 130.95, 137.10, 155.69, 167.36; IR (KBr) 2950, 2860, 1715, 1635, 1605, 1480, 1290, 1210 cm1 ; MS m/e (rel. intensity) 316 (33, 285(7), 260 (33), 259 (100), 200 (11), 185 (13), 141 (8). ##STR28##

Workup

  1. customA 10 mL round bottom flask fitted with magnetic stirrer
  2. customhad been dried by vacuum distillation from CaH2
  3. extractionextracted with 3-35 mL portions of pentane
  4. washThe combined pentane solutions were washed with 25 mL of water, 25 mL of brine
  5. dry with materialdried over MgSO4
  6. customEvaporation of the pentane
  7. customyielded 1.45 g of slightly yellow solid
  8. customPurification by column chromatography on silica using 5% (V/V) ethyl acetate/hexane as eluent

Sources & evidence

ORD record
ord-c298818a38c74c62be247f29f1f45b73
Source dataset
uspto-grants-1998_01
Patent number
US05707559

Reaction notes

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