Isatin → HCID 553397, compound

HRID 520773Notes

Reaction equation

HRID 520773 reaction equation
[Si:1](Cl)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[NH:9]1[C:19]2[C:14](=[CH:15][CH:16]=[CH:17][CH:18]=2)[C:12](=[O:13])[C:10]1=[O:11].C(N(CC)CC)C>ClCCl.CN(C)C1C=CN=CC=1>[Si:1]([N:9]1[C:19]2[C:14](=[CH:15][CH:16]=[CH:17][CH:18]=2)[C:12](=[O:13])[C:10]1=[O:11])([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2]

Participants

6

Reactant 3

HCID 7054IsatinHCID 8471TriethylamineHCID 28928tert-Butyldimethylsilyl chloride

Product 1

HCID 553397HCID 553397, compoundYield 67%

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 6344DichloromethaneSolvent

Conditions

Temperature
22 °C

Procedure

In a 250 mL flame dried round bottom flask equipped with a stir bar, tert-butyldimethylsilyl chloride (4.5 g, 30 mmol) is dissolved in 150 mL dichloromethane. To this solution, in a single portion, isatin (2.2 g, 15 mmol) and 4-dimethylaminopyridine (0.18 g, 1.5 mmol) are added. The flask is sealed with a rubber septum and purged with nitrogen. Triethylamine (6.3 mL, 45 mmol) is added in one portion through a syringe and mixture is allowed to stir for 24 h at 22° C. The volatiles are removed in vacuo and the resultant dark orange solid is purified by silica gel chromatography (hexanes to 1:1 hexanes:dichloromethane to dichloromethane) to afford an orange solid, which is recrystallized from hot EtOH (details below) to afford 14a (2.6 g, 9.9 mmol, 67% yield) as an orange crystalline solid. Please note that for long-term storage, N-tert-butyldimethylsilyl protected isatins should be kept under an inert atmosphere at −15° C. 1-(tert-Butyldimethylsilyl)indoline-2,3-dione (14a): M.p.=123-124° C. IR (neat): 2929 (w), 2853 (w), 1731 (s), 1603 (m), 1589 (m), 1463 (m), 1325 (m), 1252 (m), 1170 (m), 1139 (m), 927 (m), 835 (s), 796 (m), 752 (s), 686 (m), 466 (m), 424 (m) cm−1; 1H NMR (400 MHz, CDCl3): δ 7.63-7.61 (1H, m), 7.53-7.49 (1H, m), 7.10-7.03 (2H, m), 1.02 (9H, s), 0.56 (6H, s); 13C NMR (100 MHz, CDCl3): δ 184.2, 164.9, 155.4, 138.3, 125.6, 123.4, 120.0, 115.1, 26.4, 19.7, −3.3; HRMS Calcd for C14H20NO2Si [M+H]+: 262.12633. Found: 262.12608.

Workup

  1. temperatureIn a 250 mL flame
  2. customdried round bottom flask
  3. customequipped with a stir bar
  4. customThe flask is sealed with a rubber septum
  5. custompurged with nitrogen
  6. customThe volatiles are removed in vacuo
  7. customthe resultant dark orange solid is purified by silica gel chromatography (hexanes to 1:1 hexanes:dichloromethane to dichloromethane)
  8. customto afford an orange solid, which
  9. customis recrystallized from hot EtOH (details below)

Sources & evidence

ORD record
ord-b394f283aecb41c78ab3aced3fcd6d84
Source dataset
uspto-grants-2016_05
Patent number
US09328061B2

Reaction notes

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