5-Bromoisatin → 5'-Bromospiro[[1,3]dioxane-2,3'-indolin]-2'-one

HRID 853866

Reaction equation

HRID 853866 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][C:6](=[O:11])[C:5]2=[O:12].[CH2:13](O)[CH2:14][CH2:15][OH:16].O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1C=CC=CC=1>[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][C:6](=[O:11])[C:5]12[O:16][CH2:15][CH2:14][CH2:13][O:12]1

Participants

5

Reactant 3

HCID 68895-BromoisatinHCID 104421,3-PropanediolHCID 521998p-Toluenesulfonic acid monohydrate

Product 1

HCID 7115935'-Bromospiro[[1,3]dioxane-2,3'-indolin]-2'-oneYield 46%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

A mixture of 5-bromoisatin (5.00 g, 22.1 mmol), 1,3 propanediol (4.86 mL, 66.4 mmol, 3 eq) and p-toluenesulfonic acid monohydrate (0.84 g, 4.42 mmol, 0.2 mole %) in benzene (430 mL) was refluxed with a Dean Stark Trap for 5 hr. The mixture was concentrated and washed with sat. aq. NaHCO3 (2×) and brine (1×) and flash chromatographed (Biotage KP silica gel, step gradient 70/30-60/40 Petroleum ether/EtOAc) to give the title compound as a bright yellow solid (2.86 g, 46% ). Anal. Calc'd for C11H10BrNO3: C, 46.50; H, 3.55; N, 4.93. Found: C, 46.82; H, 3.54; N, 4.82. IR: consistent. NMR (300 Mz, DMSO-d6): consistent. MS: (ESI−) m/z 281/283 [M−H], 1 Br pattern observed. m.p.: 202-203° C.

Workup

  1. temperaturewas refluxed with a Dean Stark Trap for 5 hr
  2. concentrationThe mixture was concentrated
  3. washwashed with sat. aq. NaHCO3 (2×) and brine (1×) and flash
  4. customchromatographed (Biotage KP silica gel, step gradient 70/30-60/40 Petroleum ether/EtOAc)

Sources & evidence

ORD record
ord-f3c0bf357a6e44ab8054e767dfec4b08
Source dataset
uspto-grants-2007_08
Patent number
US07256198B2

Linked notes

Loading…