Title:
MANUFACTURE OF VITAMIN B6
Document Type and Number:
WIPO Patent Application WO2003027121
Kind Code:
A3
Abstract:
A process for the manufacture of a =:1-1,3-dihydrofuro[ 3,4-c] pyridine (I) 1 which is 4,7-disubstituted with a readily cleavable group (R) involves reacting a bis(3-R- substituted 2-propynyl) ether of the formula (R-CC-CH2)2O (II) with acetonitrile in the presence of a cobalt(I) complex catalyst of the formula XCo(I)Ligl/2 (III), wherein X signifies cyclopentadienyl, acetylcyclopentadienyl, indenyl or phenylborinato and Lig1/2 signifies the cyclooctadiene or norbornadiene ligand (Lig1) or two carbonyl or ethene ligands (Lig2), in an aliphatic, alicyclic or aromatic hydrocarbon solvent, or in excess acetonitrile as the reagent and simultaneously the solvent, or in water alone or in admixture with an ethereal co-solvent, or in a mixture of two or more of the aforementioned types of solvents, at a temperature in the range from about O°C to about 80°C, under light irradiation at wavelengths from about 300 nm to about 800 nm and with as much exclusion of atmospheric oxygen as possible. The so-produced 4,7-di(R)- substituted 6-methyl-1,3-dihydrofuro[3,4-c]pyridine is useful as an intermediate in the multistage process for manufacturing vitamin B6, especially pyridoxine. The invention further concerns the novel bis(3-R'-substituted 2-propynyl) ethers of the formula (R'-CC-CH2)2O (II'), wherein R' signifies a tri(C2-8-alkyl)silyl group, and the novel 4,7- di(R')-substituted 6-methyl-1,3-dihydrofuro [3,4-c] pyridines.
Inventors:
BONRATH WERNER (DE)
HELLER BARBARA (DE)
HELLER BARBARA (DE)
Application Number:
PCT/EP2002/010226
Publication Date:
October 16, 2003
Filing Date:
September 12, 2002
Export Citation:
Assignee:
ROCHE VITAMINS AG (CH)
BONRATH WERNER (DE)
HELLER BARBARA (DE)
BONRATH WERNER (DE)
HELLER BARBARA (DE)
International Classes:
C07F7/08; (IPC1-7): C07F7/08
Other References:
PARNELL, CAROL A. ET AL: "The cobalt way to vitamin B6. Regioselective construction of the tetrasubstituted pyridine nucleus by cobalt-catalyzed alkyne-nitrile cooligomerizations", TETRAHEDRON (1985), 41(24), 5791-6, 1985, XP002230595
GEIGER, RUDOLF E. ET AL: "Cobalt-catalyzed cycloaddition of alkynes and nitriles to pyridines: a new route to pyridoxine (vitamin B6)", HELVETICA CHIMICA ACTA (1984), 67(5), 1274-82, 1984, XP002230596
SUGIHARA, TAKUMICHI ET AL: "Synthesis of cyclopentadienones catalyzed by methylidynetricobalt nonacarbonyl", CHEMICAL COMMUNICATIONS (CAMBRIDGE, UNITED KINGDOM) (2001), (23), 2456-2457, 2001, XP002242871
GEIGER, RUDOLF E. ET AL: "Cobalt-catalyzed cycloaddition of alkynes and nitriles to pyridines: a new route to pyridoxine (vitamin B6)", HELVETICA CHIMICA ACTA (1984), 67(5), 1274-82, 1984, XP002230596
SUGIHARA, TAKUMICHI ET AL: "Synthesis of cyclopentadienones catalyzed by methylidynetricobalt nonacarbonyl", CHEMICAL COMMUNICATIONS (CAMBRIDGE, UNITED KINGDOM) (2001), (23), 2456-2457, 2001, XP002242871
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