Chloroform → HCID 131726705, compound

HRID 403177Notes

Reaction equation

HRID 403177 reaction equation
C([O:8][C:9]([C:11]1[CH:29]=[CH:28][C:14]2[O:15][CH2:16][CH:17]([C:19]([CH3:27])([CH3:26])[O:20][SiH2:21][C:22]([CH3:25])([CH3:24])[CH3:23])[O:18][C:13]=2[C:12]=1[CH3:30])=[O:10])C1C=CC=CC=1.[H][H].C(Cl)(Cl)Cl>C(Cl)Cl.[Pd]>[C:22]([SiH2:21][O:20][C:19]([CH3:27])([CH3:26])[CH:17]1[CH2:16][O:15][C:14]2[CH:28]=[CH:29][C:11]([C:9]([OH:10])=[O:8])=[C:12]([CH3:30])[C:13]=2[O:18]1)([CH3:25])([CH3:23])[CH3:24]

Participants

6

Reactant 3

HCID 6212ChloroformHCID 131726706HCID 131726706, compoundHCID 178418361HCID 178418361, compound2×

Product 1

HCID 131726705HCID 131726705, compoundYield 85.1%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 6344DichloromethaneSolvent

Procedure

9.63 g of 3-(tert-Butyl-dimethyl-silanyloxymethyl)-5-methyl-2,3-dihydro-benzo[1,4]dioxine-6-carboxylic acid benzyl ester was dissolved in ca. 125 mL of dry CH2Cl2. The solution was transferred to a Parr hydrogenation bottle, and 5 g of 5% Pd on carbon were added. The bottle was charged with hydrogen and shaken on a Pair hydrogenation apparatus for 3 hours; hydrogen uptake ceased after 2 hours, as indicated by pressure monitoring. 100 mL CHCl3 were added, and the Pd/C was filtered off after adding MgSO4 as an aid to increase particle size. The CH2Cl2-CHCl3 phase was washed with 200 mL of 0.1N HCl to remove the by-product benzyl alcohol. The organic layer was dried and evaporated to give 6.47 g 3-(tert-butyl-dimethyl-silanyloxymethyl)-5-methyl-2,3-dihydro-benzo[1,4]dioxine-6-carboxylic acid, after trace solvent removal in a vacuum oven. TLC Rf=0.55 (1:1 ethyl acetate:hexane). Note: (a) Pd catalyzed hydrogenation is a far superior method to triethylsilane/palladium diacetate for this benzyl ester cleavage, (b) washing product with weak aqueous acid is a good way to remove benzyl alcohol. 1H NMR (300 MHz, CDCl3) δ (ppm): 7.55 (d, 1H), 6.7 (d, 1H), 4.3 (d, 1H), 4.17 (m, 1H), 4.02 (dd, 1H), 3.82 (dd, 1H), 3.75 (dd, 1H), (2.45 (s, 3H), 0.8 (s, 9H), 0.01 (s, 3H).

Workup

  1. additionwere added
  2. filtrationthe Pd/C was filtered off
  3. additionafter adding MgSO4 as an aid
  4. temperatureto increase particle size
  5. washThe CH2Cl2-CHCl3 phase was washed with 200 mL of 0.1N HCl
  6. customto remove the by-product benzyl alcohol
  7. customThe organic layer was dried
  8. customevaporated

Sources & evidence

ORD record
ord-3a23f571a0fe43b5ab02faa364acbd83
Source dataset
uspto-grants-2014_06
Patent number
US08748125B2

Reaction notes

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