Appeal No. 96-2322 2
Application No. 08/112,478
THE INVENTION
The invention is directed to a process of producing oxamide, i.e., oxalic acid
diamide. The process requires melting a starting material and reacting it with ammonia.
The initial melt contains oxalic acid diester and the optional presence of limited amounts
of aliphatic alcohol. During the reaction the content of the aliphatic alcohol is maintained
within specified limits. The oxamide obtained from the reaction is directly dried from a
wetted solid. Additional limitations are disclosed in the following illustrative claim.
THE CLAIM
Claim 14 is illustrative of appellants’ invention and is reproduced below.
Claim 14. A process for producing oxamide comprising the step of:
(a) melting a starting material consisting essentially of 70 to 100% by weight
of an oxalic acid diester of an aliphatic alcohol and 0 to 30% by weight of
the same aliphatic alcohol as mentioned above;
(b) feed-mixing an ammonia-containing gas to the resulting melt of the starting
material, while stirring, to start a reaction of the oxalic acid diester of the
aliphatic alcohol with ammonia to produce oxamide and a by-product
consisting of the aliphatic alcohol;
(c) continuing the feed-mixing procedure of the ammonia-containing gas under
reaction conditions sufficient to convert said diester to oxamide and, while
stirring, controlling the feed rate of ammonia, and evaporating and
removing the aliphatic alcohol by-product from the reaction mixture to an
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