1-Boc-5-formylindoline

1-Boc-5-formylindoline Property

Boiling point:

382.1±41.0 °C(Predicted)

Density 

1.186±0.06 g/cm3(Predicted)

storage temp. 

-20°C, sealed storage, away from moisture

pka

-2.49±0.20(Predicted)

Appearance

White to off-white Solid

Safety

HS Code 

2933998090

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P280Wear protective gloves/protective clothing/eye protection/face protection.

P301+P312IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

1-Boc-5-formylindoline Chemical Properties,Usage,Production

Synthesis

5-Bromo-1-tert-butoxycarbonyl dihydroindole (2.0 g, 6.7 mmol) and N,N-dimethylformamide (0.53 mL, 6.7 mmol) were used as raw materials and dissolved in tetrahydrofuran (30 mL). The resulting solution was cooled to -78 °C under stirring and a pentane solution of tert-butyllithium (1.7 M, 10.3 mL, 17.5 mmol) was added slowly and dropwise over 5 min under nitrogen protection. After the reaction mixture was stirred at -78 °C for 2 h, acetic acid (3 mL) was added. Subsequently, the cloudy mixture was slowly warmed to room temperature over 30 min and diluted with ethyl acetate (100 mL). The organic phase was washed sequentially with saturated sodium carbonate solution (2 × 10 mL) and brine (10 mL). The organic layer was dried over anhydrous sodium sulfate, filtered and concentrated in vacuum to give the crude product as an oil. Purification by column chromatography (eluent: ethyl acetate/hexane, 1:9 to 1:1 gradient elution) and vacuum removal of the solvent resulted in the isolation of two products, both white solids: (1) 1-tert-butoxycarbonyldihydroindole (270 mg, 18% yield): 1H NMR (CDCl3, 300 MHz): δ 7.18-7.10 (m, 2H), 6.92 (t 1H, J = 7 Hz), 3.97 (t, 2H, J = 7 Hz), 3.08 (t, 2H, J = 7 Hz), 1.57 (s, 9H); MS (APCI+): m/z 220 ([C13H18NO2 + H]+); (2) 1-Boc-5-formylindoline (650 mg, 39% yield): 1H NMR (CDCl3 , 300 MHz): δ 9.86 (s, 1H), 7.9 (br s, 1H), 7.70-7.65 (m, 2H), 4.06 (t, 2H, J = 7 Hz), 3.15 (t, 2H, J = 7 Hz), 1.58 (s, 9H); MS (ES+): m/z 248 ([C14H18NO3 + H]+).

References

[1] Patent: US2006/63799, 2006, A1. Location in patent: Page/Page column 11