Synthesis of Dimethyl Hexane-1,6-dicarbamate with Methyl Carbamate as Carbonyl Source over MCM-41 Catalyst.

ABSTRACT: Dimethyl hexane-1,6-dicarbamate (HDC), the vital intermediate for nonphosgene production of hexamethylene-diisocyanate (HDI), was effectively synthesized via carbonylation of 1,6-hexanediamine (HDA) using methyl carbamate (MC) as a carbonyl source over a silanol-rich MCM-41 catalyst. The effects of reaction conditions, including the reaction temperature, molar ratio of raw materials, methanol dosage, catalyst dosage, and reaction time, on the HDC yield were evaluated. Under the reaction conditions with a reaction temperature of 190 °C, a molar ratio of HDA, MC, and methanol of 1:6:50, a catalyst dosage of 10 wt %, and a reaction time of 3 h, the yield of HDC can reach as high as 92.6% with 100% HDA converted. Characterizations based on N₂ physical adsorption/desorption, scanning

SUBMITTER: Cao J 

PROVIDER: S-EPMC11447869 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature