3,4-dihydro-2H-1,4-benzoxazin-6-ol

3,4-dihydro-2H-1,4-benzoxazin-6-ol Property

Boiling point:

334.7±42.0 °C(Predicted)

Density 

1.241±0.06 g/cm3(Predicted)

vapor pressure 

0.002Pa at 20℃

storage temp. 

Keep in dark place,Inert atmosphere,Room temperature

solubility 

Chloroform (Slightly, Heated, Sonicated), DMSO (Sparingly), Methanol (Slightly)

form 

Solid

pka

10.85±0.20(Predicted)

color 

Black

Water Solubility 

19g/L at 20℃

Stability:

Hygroscopic

InChI

InChI=1S/C8H9NO2/c10-6-1-2-8-7(5-6)9-3-4-11-8/h1-2,5,9-10H,3-4H2

InChIKey

HWWIVWKTKZAORO-UHFFFAOYSA-N

SMILES

O1C2=CC=C(O)C=C2NCC1

LogP

0.219 at 23℃

Safety

HS Code 

2934999090

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

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

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

3,4-dihydro-2H-1,4-benzoxazin-6-ol Chemical Properties,Usage,Production

Flammability and Explosibility

Not classified

Synthesis

General procedure for the synthesis of 3,4-dihydro-2H-benzo[b][1,4]oxazin-6-ol from 6-hydroxy-2H-benzo[b][1,4]oxazin-3(4H)-one: 6-Hydroxy-2H-benzo[b][1,4]oxazin-3(4H)-one (0.39 g, 2.35 mmol) was dissolved in tetrahydrofuran (THF) and at 0 °C 1 M borane-THF solution (7.05 mL, 7.05 mmol) was slowly added dropwise for a controlled time of 5 min. After the dropwise addition, the reaction mixture was gradually warmed to room temperature and stirred overnight. Upon completion of the reaction, the excess borane was quenched by careful addition of methanol. Subsequently, the solvent was removed by distillation under reduced pressure and the crude product was extracted with ethyl acetate (EtOAc) to afford pure 3,4-dihydro-2H-benzo[b][1,4]oxazin-6-ol as an oil in quantitative yield (0.34 g). The product was confirmed by nuclear magnetic resonance hydrogen spectroscopy (1H NMR, DMSO-d6): δ 8.48 (s, 1H), 6.37 (d, 1H, J = 8.47 Hz), 5.96 (d, 1H, J = 2.75 Hz), 5.82 (dd, 1H, J = 8.44, 2.76 Hz), 3.97 (t, 2H, J = 4.38 Hz), 3.18 ( t, 2H, J = 4.31 Hz). Nuclear magnetic resonance carbon spectrum (13C NMR, DMSO-d6): δ 152.2, 136.6, 135.8, 116.7, 103.8, 102.0, 65.0, 47.2. electrospray high-resolution mass spectrometry (ES-HRMS) measured [M + H]+ as 152.0711, which is in accordance with the theoretically calculated value (C8H10NO2).

References

[1] Patent: WO2009/36351, 2009, A2. Location in patent: Page/Page column 21; 22/24