The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 15, 1979
Filed:
Feb. 06, 1978
Reinhard H Richter, North Haven, CT (US);
Benjamin W Tucker, Bethany, CT (US);
Henri Ulrich, Northford, CT (US);
The Upjohn Company, Kalamazoo, MI (US);
Abstract
A novel process is disclosed for the preparation of cyclic ureas having the formula ##STR1## wherein A is a straight chain alkylene radical of 2 to 4 carbon atoms, inclusive, wherein said alkylene radical can be substituted by at least one member selected from the group consisting of halogen, lower alkyl, lower alkoxy, aryl, aryloxy, aralkyl, and cycloaklyl. An alkylene diamine having the formula NH.sub.2 ANH.sub.2, wherein A is defined as above, is reacted in a solvent with carbonyl sulfide to form the corresponding N-(.omega.-aminoalkyl)thiocarbamic acid (NH.sub.2 ANHCOSH) or zwitterion thereof. The thiocarbamic acid is then heated to form the cyclic urea. The cyclic ureas are useful as cross-linkers and extenders in polyurethane formulations, and those ureas having 4 carbons in the alkylene chain find particular utility in the production of bis cyclic ureas which serve as masked isocyanate compounds in one-component polyurethane elastomer formulations.