ChemicalBook CAS DataBase List 4,4'-Diphenylmethane diisocyanate

4,4'-Diphenylmethane diisocyanate synthesis

9synthesis methods

Product Name:4,4'-Diphenylmethane diisocyanate
CAS Number:101-68-8
Molecular formula:C15H10N2O2
Molecular Weight:250.25

Phosgene (800 g, 8 mol) (for a safe source) was dissolved in o-dichlorobenzene (2000 mL), and the resulting solution was cooled in an ice-salt bath. To the stirred solution, a hot solution of 4,4'-diaminodiphenylmethane (200 g, 1.01 mol) in o-dichlorobenzene (1000 mL) was slowly added through a heated dropping funnel. The rate of addition was regulated so that the temperature of the phosgene solution did not rise substantially above 0°C. The fine suspension that resulted was slowly heated and additional phosgene (700 g, 7.1 mol) was added at 130 °C until a clear solution appeared. After purging with carbon dioxide, the solvent was removed in vacuo and the product was purified by vacuum distillation. At 156–158 °C (0.1 mmHg), 215 g (0.85 mol, 84%) of 4,4’-diphenylmethane diisocyanate was obtained. Several procedures for the preparation of isocyanates with phosgene have been described. Nevertheless, many of them require the delivery of gaseous phosgene from an external source, such as a pressurized cylinder.

7450-63-7 Synthesis

7450-63-7
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101-68-8
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Yield:101-68-8 96%

Reaction Conditions:

with zinc diacetate;1-((ethoxycarbonyl)methyl)-3-methylimidazolium tetrafluoroborate in neat (no solvent) at 25 - 230; for 0.25 h;Catalytic behavior;Mechanism;Inert atmosphere;Reagent/catalyst;Solvent;

References:

Duan;You;Liu;Ma;Zhou;Zhang;Zhang [New Journal of Chemistry,2018,vol. 42,# 14,p. 12243 - 12255]