Herstellung von aliphatischen Diisocyanaten ohne Anwendung von Phosgen

Abstract

Preparation of Aliphatic Diisocyanates without Using of Phosgene Das Hauptausgangsmaterial für die Synthese des modernen Typs von Polyurethanlacken, die gegen das Licht widerstandsfähig sind, bilden die aliphatischen Diisocyanate [1–4]. Diese Verbindungen werden im größeren Maßstab durch Phosgenierung entsprechender Diamine gewonnen. Die Methode ist aber für Mensch und Umgebung gefährlich [5].

Sustainable routes to polyurethane precursors

“…In 1979, Lesiak and Seyda described a method for the synthesis of isocyanates from formamides. 33 After optimization, they found that the highest yields were obtained if formamides were heated with an excess of bromine in benzene in the presence of 1,4-diazabicyclo[2.2.2]-octane (DABCO) to obtain isocyanates in moderate yields (Scheme 5). The addition of DABCO is necessary to bind the released hydrogen bromide.…”

Formyl C−H···O Hydrogen Bonding in Crystalline Bis-Formamides?

“…In our molecular recognition studies of formyl groups, we noticed that bis-formamides of the formula HCO(NH)(CH 2 ) n (NH)OCH ( n = 4−7) show a striking (35 °C) melting point alternation for odd and even chains (Figure ) ), and its absence in the odd-chain crystals (which we have been unable to grow for X-ray diffraction studies)…”

“…The 35 °C alternation for n = 4−7 (dashed lines) highlights the difference in H-bonding complementary for the even and odd chains. Melting points (°C) are 2:105, 4:92.5, 5:64.5, 6:106.5, 7:77.5, 8:87 (for n : mp).

2 ORTEP packing diagrams showing (a) the 1̄ motif for antiparallel ribbons that form a layer of ODDF ([001] vertical) and (b) the 2 1 layer motif for BDDF ([010] vertical). Selected intra- and intermolecular distances (Å) and angles (deg) for the formyl−formyl interactions are given here: BDDF C−H 0.96(3), C···O 3.378(5), H···O 2.44(3), C−H···O 166(3), C−O···H 102.8(8); ODDF C−H 0.96(3), C···O 3.345(3), H···O 2.60(3), C−H···O 135(2), C−O···H 101.1(6).

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“…The 35 °C alternation for n = 4−7 (dashed lines) highlights the difference in H-bonding complementary for the even and odd chains. Melting points (°C) are 2:105, 4:92.5, 5:64.5, 6:106.5, 7:77.5, 8:87 (for n : mp).…”

Isobaric Vapor–Liquid Equilibrium for Binary Mixtures Composed of Pentamethylene Diisocyanate, 5-Chloropentyl Isocyanate, and Chlorobenzene at 10 kPa

“…The Antoine parameter values for pentamethylene diisocyanate and 5-chloropentyl isocyanate were both obtained through regression of experimental data in Aspen Plus. − The Antoine parameter values for chlorobenzene, however, were sourced from the Aspen Plus database, with detailed parameters available in Table . The binary phase equilibrium data for the mixtures of pentamethylene diisocyanate + 5-chloropentyl isocyanate, pentamethylene diisocyanate + chlorobenzene, and 5-chloropentyl isocyanate + chlorobenzene, along with their corresponding calculated activity coefficients, can be found in Tables – , respectively.…”