1,8-Diaminooctane 373-44-4

1,8‑Octanediamine
CAS No.: 373‑44‑4
Properties
Melting Point: 50‑52 °C(lit.)
Boiling Point: 225‑226 °C(lit.)
Density: 0.98 g/mL at 20 °C
Vapor Pressure: <0.1 hPa (20 °C)
Refractive Index: 1.4618 (estimate)
Flash Point: 329 °F
Storage Condition: Store below +30 °C.
Solubility: 575 g/L
Form: Solid crystalline
pKa: 11.00, 10.1 (at 20℃)
Color: White to yellow
pH Value: 11.7 (4 g/L, H₂O, 20℃)
Explosive Limit: 1.1‑6.8% (V)
Water Solubility: 575 g/L (20ºC)
Sensitivity: Hygroscopic
BRN: 1735426
InChI: 1S/C8H20N2/c9‑7‑5‑3‑1‑2‑4‑6‑8‑10/h1‑10H2
InChI Key: PWGJDPKCLMLPJW‑UHFFFAOYSA‑N
SMILES: NCCCCCCCCN
LogP: 0.896 at 25℃
CAS Database Reference: 373‑44‑4
NIST Chemical Information: 1,8‑Diaminooctane (373‑44‑4)
EPA Chemical Information: 1,8‑Octanediamine (373‑44‑4)
Uses & Synthesis Method
Uses
1,8‑Octanediamine is an organic amine compound. Organic amines are widely applied in organic synthesis for agrochemicals, pharmaceuticals, detergents, polymers and other fields. As a comonomer for high‑performance polymers, 1,8‑octanediamine possesses great industrial value.
Synthesis Method
1,8‑Octanediamine can be synthesized using 1,6‑dicyanohexane as starting material. General process is described as below:
Equip a 500 mL autoclave with thermocouple thermometer, two‑piece inclined‑blade stirrer, pressure gauge and hydrogen purging pipeline. Charge 175 g 1,6‑dicyanohexane, 86.0 g methanol, 2.0 g 28% sodium methacrylate‑methanol solution (0.64 wt%), and 10.5 g nickel‑based catalyst (6.0 wt% nickel metal basis relative to 1,6‑dicyanohexane). The water content of the solution is measured as 920 ppm by Karl Fischer moisture meter (Hiranuma Sangyo Co.,Ltd.).
After feeding, perform hydrogen replacement and raise pressure to 5 MPa. Heat the system to internal temperature 90 °C within about 1 hour. Hydrogen consumption can be observed starting at approximately 70 °C. Maintain reaction at 90 °C; hydrogen consumption nearly ceases after around 6 hours. Keep reaction for another 2 hours, then cool down to room temperature and release pressure. Filter the reaction mixture to remove catalyst, and wash filter cake with 100 g methanol. The total weight of obtained 1,8‑octanediamine methanol solution is 377.4 g. GC analysis shows 94.3% peak‑area content of 1,8‑octanediamine, corresponding to reaction yield of 96.7%.
References
[1] Patent: JP2017/31143, 2017, A. Paragraph 0082; 0083; 0086; 0087
[2] Chemische Berichte, 1913, vol. 46, p. 230
[3] Patent: US6376714, 2002, B1
[4] Patent: US2011/313186, 2011, A1. Page 11