Title:
PREPARATION OF D,L-MENTHOL
Document Type and Number:
Japanese Patent JP3413608
Kind Code:
B2
Abstract:
PURPOSE: To industrially advantageously prepare d,1-menthol by continuously hydrogenating a compd. having a menthol, skeleton such as thymol with a catalyst consisting of an active component such as Pd or Ru, a specified alkali metallic salt as a promoter and a carrier contg. specified metals.
CONSTITUTION: An arom. compd. or a partly hydrogenated cyclic compd. having the carbon skeleton of menthol having at least one double bond and substd. by oxygen in the 3-position relative to the methyl group is catalytically hydrogenated to obtain the objective d,1-menthol. At this time, a catalyst consisting of Pd, Ru, Rh or a mixture of these elements as active components, one or more alkali metallic hydroxide and/or alkali metallic sulfates as promoters and a carrier treated with a rare earth metal and Mn is used. The amt. of hydrogen used per 1 mol starting material is made 5 times the amt. of hydrogen required to hydrogenate the benzene nucleus and hydrogenation is carried out at 160-220°C and at least 25 bar pressure. Continuous hydrogenation is enabled on an industrial scale by using the catalyst.
Inventors:
Otto Immel
Gerhard Dalsow
Hans-Joseph Bouiscyu
Gerhard Dalsow
Hans-Joseph Bouiscyu
Application Number:
JP7873893A
Publication Date:
June 03, 2003
Filing Date:
March 12, 1993
Export Citation:
Assignee:
Bayer Aktiengesellschaft
International Classes:
B01J23/656; B01J27/055; C07B61/00; C07C29/17; C07C29/20; C07C35/12; (IPC1-7): C07C35/12; B01J23/656; B01J27/055; C07C29/20
Domestic Patent References:
| JP275343A |
Other References:
Ｃ．Ｒ．Ｓｅａｎｃｅｓ Ａｃａｄ．Ｓｃｉ．，Ｓｅｒ．Ｃ，１９８０年，２９１（８），ｐ．２１９−２２１
Ｉｚｖ．Ａｋａｄ．Ｎａｕｋ Ｋａｚ．ＳＳＲ，Ｓｅｒ．Ｋｈｉｍ．，１９９０年，（２），ｐ．４９−５２
Ｉｚｖ．Ａｋａｄ．Ｎａｕｋ Ｋａｚ．ＳＳＲ，Ｓｅｒ．Ｋｈｉｍ．，１９９０年，（２），ｐ．４９−５２
Attorney, Agent or Firm:
Heikichi Odashima