DE589779C - Process for the addition of fatty acids to camphene using boron fluoride as a catalyst - Google Patents

Description

GERMAN EMPIRE

REICH PATENT OFFICE

PATENT ISSUED DECEMBER 14, 1933

CLASS 12 ο GROUP

12 0 Γγ97

It is known that fatty acids, such as formic acid or acetic acid, can be added to camphene with the aid of catalysts, e.g. B. sulfuric acid, phosphoric acid, zinc chloride, etc. A significant excess of fatty acid and use of elevated temperature are necessary to obtain a high yield of ester in the shortest possible time. So is z. B. according to the patent specification 67 255, an excess of 470 ° / ₀ of acetic acid is required. After the esterification, this excess must be removed by distillation or washing. Although the addition of the highly concentrated formic acid succeeds even without a catalyst, it either requires an excess of 500 ° / ₀ at room temperature or, if only a small excess (26%) is to be used, a higher temperature above the boiling point of the formic acid.

In the Annalen der Chemie, Vol. 4ζζ, pp. 248 to 250, it is stated that weak acids are significantly strengthened by so-called Ansolvo acids. The Ansolvo acids also form esterification catalysts. I.a. the esterification of camphene with acetic acid in the presence of zinc chloride is given. As an aside, it is generally noted

(P. 249) ,. that other Ansolvo acids, such as sulfur dioxide, boron trioxide, pyroboroacetate and boron fluoride, have to a greater or lesser extent the same property.

It has now been found that by using boron fluoride as a catalyst is carried out the addition of fatty acid to camphene in a short time and in very good yield when amounts equivalent or an excess of at most 20 ° / ₀ applies to fatty acid. It is advisable to cool to avoid damaging temperature increases.

A success of the present procedure was compared to the cited work in the Annals cannot be foreseen, because there it is stated that boron fluoride has a terpene reacts with the greatest violence with polymerization and decomposition and therefore It had to be feared that polymerization as an unpleasant accompanying reaction would also occur in the relatively low dilution would occur in the present process.

Examples

i. 100 g camphene 96%> 53 g glacial acetic acid 100% and ι g boron fluoride dissolved in a little glacial acetic acid are combined with stirring. The initially cloudy liquid clears up very quickly and warms up to about 50 ^° C. It is left to stand for some time at room temperature. After washing; with water? 142 g of crude ester are

Speaking 95% Isoborny lacetat obtained corresponding to a 99% esterification.

2. 100 g of 97% pure camphene "> 4 ^Χ> 5 § 99 ° formic acid / oig and 0.4 g Bornuorid are combined with agitation and maintained at a temperature of 50 °. The initially cloudy mixture clears up rapidly The resulting. Ester values

after 2 hours 92.9 ° / _tt ester at 50 ⁰ C,
after a further 4 ¹ J * Hours 94.6 ° / ₀ ester

at 50 ° C,
after a further 14Y ₂ hours 97.0%. Ester at room temperature (133 g),

corresponding to a 100 ° _o by weight esterification /.

3. Proceed as indicated in Example 2, but by using the self-heating is canceled by cooling to room temperature, the ester values are

after ι hour 76.6 ° / ₀ esters, after a further hour 84.6% ester, after a further 4 ¹ / "Hours 92.3 ° / ₀ esters, after a further 14 hours ¹ ^ 95.3 ° / o ester,

corresponding to a 97.3 "subsequent esterification.

Claims (1)

Claim: Method for the attachment of fatty acids to camphene using of boron fluoride as a catalyst, characterized in that the fatty acid in in an equivalent ratio or in an excess of not more than 25%.