Selective aldolization of acetone to diacetone alcohol by a solid basic catalyst
AssigneeElf Atochem S.A.
InventorsRemy Teissier, Didier Tichit, Fran.cedilla.ois Figueras, Jacques Kervennal
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Abstract
The aldolization is characterized by the use of a solid basic catalyst which has the following general formula (Mg.sup.2+).sub.1-x (Al.sup.3+).sub.x (OH.sup.-).sub.2 !.sup.+x (OH.sup.-).sub.x (H.sub.2 O).sub.n !.sup.-x (II) wherein 0.20.ltoreq.x.ltoreq.0.33 and n has a value of less than 1. This catalyst has a defined crystal structure similar to that of hydrotalcite or, alternatively, of meixnerite. Also disclosed are processes for the preparation of the catalyst.
Claims4
A process for the selective aldolization of acetone to diacetone alcohol which comprises the step of reacting acetone in the presence of a solid basic catalyst which has the general formula:
- (Mg.sup.2+).sub.1-x (Al.sup.3+).sub.x (OH.sup.-).sub.2 !.sup.+x (OH.sup.-).sub.x (H.sub.2 O).sub.n !.sup.-x
- wherein 0.20.ltoreq.x.ltoreq.0.33 and n<1.
A process for the preparation of the catalyst of general formula:
- (Mg.sup.2+).sub.1-x (Al.sup.3+).sub.x (OH.sup.-).sub.2 !.sup.+x (OH.sup.-).sub.x (H.sub.2 O).sub.n !.sup.-x
- wherein 0.20.ltoreq.x.ltoreq.0.33 and n<1, which process comprises the steps:
- a) calcining a hydrotalcite in which x has a value such that 0.20.ltoreq.x.ltoreq.0.33 at a temperature below 800.degree. C. in order to obtain a mixed oxide of magnesium and of aluminium, and
- b) rehydrating the mixed oxide thus obtained with water in the absence of CO.sub.2.
Dependencies are inferred from the claim text.