tests—were used to compare various nickel catalysts (T- 4). The best results for hydrogenation of
the aromatic ring were obtained at 190°C, 15 MPa,
20 wt. Ni-supported catalyst NiSAT 330, but
the results of all catalysts differed in the range of
measurement error. The reaction yield of such a
reaction was 76% (of cis/trans4isopropylcyclohex-
ane carboxylic acid butyl ester) at total conversion.
The rest consists of undesirable products, e.g.
Hydrogenation of the aromatic ring of the
protected substance provided positive results. The
following experiments were focused on deprotection of pisopropylcyclohexane carboxylic acid butyl
ester to Mayol. Several reactions at a temperature
of 190°C and pressure of 15 MPa were carried out.
Four types of catalysts were tested at these conditions (T- 5). The best results (selectivity 77 and
conversion rate 52 after 6 hours) were achieved
on the G-99B-0 Pulver catalyst – the catalyst
with BaO and MnO2 additives. The comparable
selectivity was obtained using T-4466 catalysts
(a comparable amount of copper and chromium
oxides, without additives) but under lower conversion. Unsatisfactory results were obtained using
the other two catalysts. Low selectivities under low
conversions, p-cymene and p-menthane occurred as
On the basis of the previous experiments, a
larger scaled experiment was performed starting
from cuminic acid (Sigma-Aldrich; purity ≥ 98%).
Cuminic acid butyl ester was prepared by azeotropic
esterification using cuminic acid, ptoluenesulfonic
acid and butan-1-ol. The initial feed was cuminic
acid (102.8g), butan-1-ol (250 ml) and PTSA ( 1.2g).
The product was then separated by vacuum distillation under a pressure of 0.27 kPa (b.p. 125, 130°C).
The reaction yield was 88% (122g) with 98% purity.
of the reaction was 97% after 19 hours. The reaction mixture containing 82.4% of both isomers of
pisopropylcyclohexane carboxylic acid butyl ester
was then treated over G-99B-0 Pulver catalyst (F- 3)
without any purification. The achieved selectivity
was 87% at total conversion after 33 hours. The
final product (4isopropylcyclohexylmethanol) was
separated by distillation. A mixture of cis/trans4iso-
propylcyclohexylmethanol 60: 40 with 99% purity
(sum of both isomers) was obtained in a 40% yield
related on cuminic acid. Regarding the multi-step
process, the yield is satisfactory.