US 7,321,067 B2
Process for the preparation of 1,4-dialkyl-2,3-diol-1,4-butanedione
Ferdinand Naef, Seewen (Switzerland); and René Decorzant, Onex (Switzerland)
Assigned to Firmenich SA, Geneva (Switzerland)
Filed on Mar. 28, 2007, as Appl. No. 11/692,839.
Application 11/692839 is a continuation of application No. PCT/IB2005/053511, filed on Oct. 27, 2005.
Claims priority of application No. PCT/IB2004/003631 (WO), filed on Nov. 02, 2004.
Prior Publication US 2007/0167656 A1, Jul. 19, 2007
Int. Cl. C07C 45/72 (2006.01)
U.S. Cl. 568—390  [568/392] 7 Claims
 
1. A process for the preparation of a compound of formula

OG Complex Work Unit Drawing
wherein R1 represents a linear or branched C1 to C5 alkyl radical,
the process comprising performing an aldol condensation, in a water-containing reaction medium, between a glyoxal of formula

OG Complex Work Unit Drawing
wherein R1 has the same meaning as defined above,
and an α-hydroxy ketone of formula

OG Complex Work Unit Drawing
wherein R1 has the same meaning as defined above,
in the presence of catalyst of formula FeX3 or MX2, wherein M is Zn2+, Mg2+, Cu2+, Fe2+ or Ca2+ and X is a C1-C7 carboxylate, an halide or a acetylacetonate derivative of formula (R2COCHCOR2), with R2 representing a C1-C3 alkyl group or a phenyl group.