Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acid esters
Patent
1992-02-07
1993-04-27
Dees, Jose G.
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acid esters
C07C26100
Patent
active
052064123
ABSTRACT:
A selective process for the preparation of diphenylmethane diisocyanate precursors is disclosed. An alkyl phenylcarbamate or an N,N-dialkyl-N'-phenylurea is reacted with a methylene bis(alkyl carbamate) in the presence of an acid catalyst. The use of a staged addition of phenylcarbamate or phenylurea to the methylene bis(carbamate) and the use of a ramped temperature program are the keys to good selectivity to MDI dimer products.
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Kesling, Jr. Haven S.
Rodriguez Carmen L.
Shawl Edward T.
Arco Chemical Technology L.P.
Dees Jos,e G.
MacMillan Keith
Schuchardt Jonathan L.
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