skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Oxidative carbonylation of amines to carbamates

Abstract

Within the last several years, new technologies have appeared to replace phosgene for isocyanate manufacture. These include carbamate chemistries based upon dialkyl carbonate, reductive carbonylation of nitroaromatics, and oxidative carbonylation of amines. The carbamate ester can be handled safely and is reversibly cleaved to the isocyanate. The technology described here involves the preparation of both aliphatic and aromatic carbamates from an amine, alcohol, CO, oxidant, and a non-corrosive catalyst. The catalyst precursor is Pd(OAc){sub 2} and the oxidants are copper carboxylates or copper carboxylates and molecular oxygen. The latter represents a one-step carbamate synthesis with high catalyst activity, nearly quantitative conversions and alcohol selectivities greater than 90%. Operating temperatures and pressures are 80-110{degree}C and less than 500 psi, respectively. Experiments designed to probe the mechanism will be presented along with a discussion of novel (Cu(O{sub 2}CR){sub 2}){sub 2}R'NH{sub 2} complexes.

Authors:
Publication Date:
OSTI Identifier:
5276772
Report Number(s):
CONF-8704363--
Journal ID: ISSN 0569-3799; CODEN: ACPCA
Resource Type:
Conference
Resource Relation:
Journal Name: American Chemical Society, Division of Petroleum Chemistry, Preprints; (USA); Journal Volume: 32:1; Conference: American Chemical Society Division of Petroleum Chemistry, Denver, CO (USA), 5-10 Apr 1987
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; AMINES; CARBONYLATION; OXIDATION; CARBAMATES; CHEMICAL PREPARATION; PALLADIUM COMPOUNDS; CATALYTIC EFFECTS; CATALYSIS; CATALYSTS; CHEMICAL REACTION KINETICS; CHEMICAL REACTION YIELD; EXPERIMENTAL DATA; MEDIUM PRESSURE; MEDIUM TEMPERATURE; OXYGEN; CARBONIC ACID DERIVATIVES; CARBOXYLIC ACID SALTS; CHEMICAL REACTIONS; DATA; ELEMENTS; INFORMATION; KINETICS; NONMETALS; NUMERICAL DATA; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; REACTION KINETICS; SYNTHESIS; TRANSITION ELEMENT COMPOUNDS; YIELDS 020500* -- Petroleum-- Products & By-Products

Citation Formats

Waller, F.J.. Oxidative carbonylation of amines to carbamates. United States: N. p., 1987. Web.
Waller, F.J.. Oxidative carbonylation of amines to carbamates. United States.
Waller, F.J.. 1987. "Oxidative carbonylation of amines to carbamates". United States. doi:.
@article{osti_5276772,
title = {Oxidative carbonylation of amines to carbamates},
author = {Waller, F.J.},
abstractNote = {Within the last several years, new technologies have appeared to replace phosgene for isocyanate manufacture. These include carbamate chemistries based upon dialkyl carbonate, reductive carbonylation of nitroaromatics, and oxidative carbonylation of amines. The carbamate ester can be handled safely and is reversibly cleaved to the isocyanate. The technology described here involves the preparation of both aliphatic and aromatic carbamates from an amine, alcohol, CO, oxidant, and a non-corrosive catalyst. The catalyst precursor is Pd(OAc){sub 2} and the oxidants are copper carboxylates or copper carboxylates and molecular oxygen. The latter represents a one-step carbamate synthesis with high catalyst activity, nearly quantitative conversions and alcohol selectivities greater than 90%. Operating temperatures and pressures are 80-110{degree}C and less than 500 psi, respectively. Experiments designed to probe the mechanism will be presented along with a discussion of novel (Cu(O{sub 2}CR){sub 2}){sub 2}R'NH{sub 2} complexes.},
doi = {},
journal = {American Chemical Society, Division of Petroleum Chemistry, Preprints; (USA)},
number = ,
volume = 32:1,
place = {United States},
year = 1987,
month = 4
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • Oxidative carbonylation technology is used for making methyl cinnamate from styrene as an alternative to Claisen condensation of benzaldehyde with methyl acetate. Using this approach, the optimum yield of cinnamate is greater than 90%, with CO{sub 2}, acetophenone, and phenylsuccinate as the major by-products. The conversion of styrene and the selectivity to cinnamate depend upon the types of catalysts and reaction conditions used. A plausible reaction mechanism is proposed to account for the selective formation of cinnamate.
  • Graphite- and polymer- supported palladium catalysts were found to be significantly better than homogeneous palladium catalysts for carbonylation. Improvements were found in both catalyst activity and product selectivity. The supported catalysts were used to perform oxidative dicarbonylation of 1,3-butadiene and {alpha}-olefins and hydrodimerization of 1,3-butadiene.
  • Conventional technology for sebacic acid manufacture involves caustic soda decomposition of ricinoleic acid at high temperature. Principal co-products include 2-octanol and glycerine. Castor oil, which is the natural source for ricinoleic acid, is subject to price fluctuation due to cyclic crop production and protectionist policies by foreign governments. Castor oil technology is also at disadvantage because the overall product yield is low (<80%) and co-product 2-octanol must compete with cheap 2-ethylhexanol in plasticizer applications. These and other factors have resulted in a significant decline in the sebacic acid market from about 30 MM lbs. per year in the 70's tomore » less that 5 MM lbs. in the 80's. Thus, there is a clear need for a new process to produce sebacic acid from cheap and readily available petrochemicals. In Japan, the need for new technology was answered by the development of an electrolytic route to sebacic acid. The Kolbe type electrolytic process involves dimerization of adipic acid half methyl ester salt to give dimethyl sebacate. The dimerization proceeds in 92% yield with 90% selectivity based on the adipate half ester. The main drawbacks of this process are the cost of energy utilized by the electrolytic process and the cost of adipic acid. A recent Chem Systems report indicates a small advantage for the Asahi electrolytic process with ample room for new technology development.« less
  • Dimethyl carbonate (DMC) synthesis reaction by oxidative carbonylation of methanol has been studied using vapor phase flow reaction system in the presence of Cu-based catalysts. A series of Cu-based catalysts were prepared by the conventional impregnation method using activated carbon (AC) as support. The effect of various promoters and reaction conditions on the catalytic reactivities was intensively evaluated in terms of methanol conversion and DMC selectivity. The morphological change of catalysts during the reaction was also compared by X-ray diffraction and SEM analysis. Regardless of catalyst compositions, the optimal reaction temperature for oxidative carbonylation of methanol was found to bemore » around 120--130 C. The reaction rate was too slow below 100 C, while too many by-products were produced above 150 C. Among the various catalysts employed, CuCl{sub 2}/NaOH/AC catalyst with the mole ratio of OH/Cu = 0.5--1.0 has shown the best catalytic performance, which appears to have a strong relationship with the formation of intermediate species, Cu{sub 2}(OH){sub 3}Cl.« less