Abstract: The present invention relates to carbamoylation of amines, mercaptanes, thiophenols and phenols employing organic azides. More specifically, the invention relates to a method for generating urea derivatives, thiocarbamate derivatives and carbamate derivatives, and is based on the intermediate formation of isocyanate, starting from an organic azide. The reaction as described is useful in applications for modified nucleoside synthesis, oligonucleotide synthesis, as well as modification, labeling and conjugation of polymers and biomolecules.
Abstract: The invention provides a novel polyisocyanate compound which is useful as a starting material for an optical material having a high refractive index, a low dispersion and excellent optical characteristics, and a process for producing this compound at good efficiency. The invention also provides an optical material having a high refractive index, a low dispersion, an excellent transparency without optical distortion and having good solvent resistance and weatherability.
Abstract: The invention provides a novel polyisocyanate compound which is useful as a starting material for an optical material having a high refractive index, a low dispersion and excellent optical characteristics, and a process for producing this compound at good efficiency. The invention also provides an optical material having a high refractive index, a low dispersion, an excellent transparency without optical distortion and having good heat resistance.
Abstract: Novel trans-beta-isocyanatoacrylate esters, their preparation and use in forming novel polymeric compositions, including polymers useful as adhesives, are disclosed. The trans-beta-isocyanatoacrylate esters have the formula: ##STR1## wherein R is C.sub.1 -C.sub.18 linear or branched alkyls; C.sub.5 -C.sub.6 cycloalkyl; aryl; alkaryl; aralkyl; C.sub.1 -C.sub.18 halogenated alkyl; halogenated aryl; C.sub.1 -C.sub.8 alkoxyalkyl; or alkoxyaryl.
Type:
Grant
Filed:
August 11, 1994
Date of Patent:
March 28, 1995
Assignee:
Curators of the University of Missouri
Inventors:
Thomas J. Byerley, Cecil C. Chappelow, J. David Eick
Abstract: A process for preparing an isocyanate having at least two --N.dbd.C.dbd.O groups is provided which comprises preparing a substituted aromatic amine having at least two --NH.sub.2 groups, recovering the substituted aromatic amine having at least two --NH.sub.2 groups, and preparing an isocyanate from the substituted aromatic amine having at least two --NH.sub.2 groups by (1) contacting the substituted aromatic amine with CO.sub.2 under conditions sufficient to produce the corresponding ammonium carbamate salt, and reacting the ammonium carbamate salt with an electrophilic or oxophilic dehydrating agent under conditions sufficient to produce the corresponding isocyanate, or (2) contacting the substituted aromatic amine with CO.sub.
Type:
Grant
Filed:
October 15, 1992
Date of Patent:
August 3, 1993
Assignee:
Monsanto Company
Inventors:
William D. McGhee, Michael K. Stern, Thomas E. Waldman
Abstract: There are produced 2-isocyanato-2,3-dehydrocarboxylic acid esters of the general formula: ##STR1## in which R.sup.1 is a straight chain or branched C.sub.1 -C.sub.4 -alkyl group, a phenyl group or a benzyl group, R.sup.2 is hydrogen or a methyl group and R.sup.3 is hydrogen, a straight chain or branched C.sub.1 -C.sub.16 -alkyl group, a C.sub.3 -C.sub.8 -cycloalkyl group, a C.sub.1 -C.sub.6 -alkylmercapto group or a phenyl group by reacting a 2-azido-carboxylic acid ester of the general formula: ##STR2## in an inert solvent at a temperature between 0.degree. and 150.degree. C. with phosgene or diphosgene in the presence of a perrhenate. The compounds of general formula (I) can be converted into the corresponding Z- or BOC-protected 2,3-dehydro-2-amino-carboxylic acid ester with benzyl alcohol or with tert. butyl alcohol, which esters in turn are valuable building blocks for the synthesis of dehydropeptides.
Type:
Grant
Filed:
March 10, 1986
Date of Patent:
April 28, 1987
Assignee:
Degussa Aktiengesellschaft
Inventors:
Franz Effenberger, Jurgen Kuhlwein, Karlheinz Drauz