p-Toluenesulfonic acid → HCID 66930311, compound

HRID 218087Notes

Reaction equation

HRID 218087 reaction equation
[CH2:1]([O:8][C:9]([N:11]1[CH2:15][CH:14]([O:16][CH2:17][C:18]2[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=2)[CH:13]2[O:24][CH2:25]C(=O)[CH:12]12)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH:28]([O:33][CH3:34])([O:31][CH3:32])OC.CC1C=CC(S(O)(=O)=O)=CC=1>CO>[CH2:1]([O:8][C:9]([N:11]1[CH2:15][CH:14]([O:16][CH2:17][C:18]2[CH:19]=[CH:20][CH:21]=[CH:22][CH:23]=2)[CH:13]2[O:24][CH2:25][C:28]([O:31][CH3:32])([O:33][CH3:34])[CH:12]12)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 9005Trimethyl orthoformateHCID 66930122HCID 66930122, compound

Product 1

HCID 66930311HCID 66930311, compound

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
60 °C

Procedure

Compound 12a (7.6 g) was dissolved dry methanol (100 mL). Trimethyl orthoformate (30 mL) and pTsOH (0.2 g) was added at rt under a nitrogen atmosphere. The mixture was heated at 60° C. for 8 hours. Once the reaction was deemed complete according to TLC, it was cooled to rt and concentrated in vacuo. The crude product was purified by column chromatography over silica gel eluting with ethyl acetate-heptane (1:4) to afford after concentration in vacuo the ketal 12b as a clear oil (5.9 g, 71% over 2 steps); ESI+, m/z: 382 (M+ —OMe).

Workup

  1. temperaturewas cooled to rt
  2. concentrationconcentrated in vacuo
  3. customThe crude product was purified by column chromatography over silica gel eluting with ethyl acetate-heptane (1:4)
  4. customto afford
  5. concentrationafter concentration in vacuo the ketal 12b as a clear oil (5.9 g, 71% over 2 steps)

Sources & evidence

ORD record
ord-8375ef534a7a4645a02c5af436386747
Source dataset
uspto-grants-2012_06
Patent number
US08198283B2

Reaction notes

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