Example D-optimal design for screening of variables in enamine synthesis

2 J Example D-optimal design for screening of variables in enamine synthesis 

A procedure was studied by which enamines are produced by the condensation of the parent ketones and a secondary amine in the presence of molecular sieves. The molecular sieves are used to trap the water which is formed.[6] The enamine formation is acid catalyzed both BrOnsted adds and Lewis adds can be used as catalysts.[7] 

The condensation of methyl isobutyl ketone and morpholine in the presence of two commerdally available zeolite-type molecular sieves (Type 3A and 5A) was used as a model reaction. The procedure was known with other systems, although the conclusions on the amounts of amine to be used were contradictoiy.[8] These ambiguities needed to be clarified. 

To determine suitable experimental conditions for preparative nms, the important experimental variables should be known. To determine this, a D-optimal design was used. The variables which were studied are summarized in Table 7.1. 

Some interactions between the variables could be expected  

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