p-Toluenesulfonic acid → HCID 66930311, compound

HRID 1366303Notes

Reaction equation

HRID 1366303 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

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-a0da908a5b834dd1989562952a3e88bf
Source dataset
uspto-grants-2011_02
Patent number
US07893067B2

Reaction notes

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