CS209377B1 - Cleaning method of 3-phenyl-1-propanole and 3-phenyl-1-butanole - Google Patents

Description

The present invention relates to a process for the purification of 3-phenyl-1-propanol and 3-phenyl-1-butanol prepared by hydrogenolysis of 4-phenyl-1,3-dioxane and 4-phenyl-4-methyl-1,3-dioxane.

The arylsubstituted primary alcohols find use primarily in perfumery as such or as intermediates for the preparation of esters, aldehydes, acids and other chemical compounds also useful in the perfumery, pharmaceutical industry, as plasticizers for plastics and the like.

Suitable starting materials for the preparation of aryl-substituted primary alcohols are 4-aryl-1,3-dioxanes, readily available by the Prins reaction of formaldehyde with arylolefins, most commonly styrene, α-methylstyrene and other substituted styrenes. The resulting 4-aryl-1,3-dioxane can then be hydrogenolytically cleaved, preferably using copper-based catalysts as disclosed in U.S. Pat. AO No. 182 114 or on the basis of copper oxide and chromium trioxide with various admixtures, as stated in the Czech patent no. AO No. 189 945.

The crude hydrogenolysis product, 3-phenyl-1-propanol or 3-phenyl-1-butanol often contains some unreacted starting material, 4-phenyl-1,3-dioxane or 4-phenyl-4-methyl-1,3-dioxane . Unreacted dioxane, even in small amounts, odorizes the product as it undergoes gradual decomposition accompanied by formaldehyde release. Since the boiling points of the corresponding alcohols and dioxanes are very close, a very efficient rectification column would be required for good distillation. This leads to an increase in investment and production costs, which is negatively reflected in the price of products.

These disadvantages are overcome by the method of purification of 3-phenyl-1-propanol and 3-phenyl-1-butanol according to the invention. Its essence lies in being raw

3-phenyl-1-propanol or crude 3-phenyl-1-butanol is distilled in the presence of p-toluenesulfonic acid added in an amount of 0.2 to 5% by weight. to the mass of the reaction mixture.

The advantage of the process according to the invention is primarily that a stable, odor-rich product is obtained which is not subject to gradual decomposition. The cost of equipment in both investment and production terms is substantially lower.

The procedure is apparent from the following examples of a specific embodiment.

He did

The crude reaction mixture from hydrogenolysis of 4-phenyl-1,3-dioxane contained 14.68 wt. % methanol, 0.11 wt. % toluene, 0.15 wt. % ethylbenzene, 6.36 wt. propylbenzene, 0.20 wt. 1-phenyl-4-oxapentane, 73.32%; % wt. % 3-phenyl-1-propanol, 0.70 wt. % methyl 3-phenoxy-1-propionate, 2.8 wt. % 4-phenyl-1,3-dioxane, 0.73 wt. % 3-phenyl-2,6,8-trioxanonan and 0.60 wt. 3-phenyl-1-propyl 3-phenyl-1-propionate. To 150 g of this mixture was added 0.4 g of p-toluenesulfonic acid. The mixture was heated to boiling and distilled. 90 g of pure 3-phenyl-1-propanol were obtained

99.9%, boiling at 117-120 ° C / 1.86 kPa.

Example 2

It was worked in an analogous way to that

Claims (1)

A process for the purification of 3-phenyl-1-propanol and 3-phenyl-1-butanol prepared by hydrogenolysis of 4-phenyl-1,3-dioxane and 4-phenyl-4-methyl-1,3-dioxane, characterized in that the crude 3-phenyl is Example 1 except that the crude reaction mixture from hydrogenolysis of 4-phenyl-4-methyl-1,3-dioxane containing 75 wt. % 3-phenyl-1-butanol, 3 wt. unreacted 4-phenyl-4-methyl-1,3-dioxane, the remaining impurities being analogous to hydrogenolysis of 4-phenyl-1,3-dioxane. After distillation, carried out in the presence of 3 wt. p-toluenesulfonic acid, based on the weight of the reaction mixture, gave 3-phenyl-1-butanol in a purity of 99.9%. OF THE INVENTION or crude 3-phenyl-1-butanol is distilled in the presence of p-toluenesulfonic acid added in an amount of 0.2 to 5% by weight. to the mass of the reaction mixture.