US1347071A - Process of oxidizing iso-borneol to camphor - Google Patents

Description

thereof.

UNITED STATES PATENT OFFICE.

ROLAND L. ANDREAU, 0F WILMINGTON,

NEMOUBS AND COMPANY,

DELAWARE, ASSIGNOB TO B. I. DU PONT 9:: OF WILMINGTON, DELAWARE, A CORPORATION OF OXIIDIZING ISO-BORNEOL T0 GAMPHOR.

Patented July 20, 1920.

DELAWARE.

PROCESS OF 1,347,071. Specification of Letters Patent. No Drawing. Application flied November 12, 1917. Serial No. 201,676.

To all whom it may concern Be it known that I, ROLAND L. ANDREAU, of \Vilmington, in the county of New Castle, and in the State of Delaware, have invented a certain new and useful Improvement in Processes of Oxidising Iso-Iiorneol to Camphor. and do hereby declare that the following is a full, clear, and exact description thereof.

My invention relates process designed for borneol into camphor particularly to a transforming isoby the oxidation ofmy invention is to provide a process of the above character in which iso-borneol is rapidly and readily transformed into camphor without depending upon the presence of a starter or catalytic agent, such as copper, sodium nitrite, starch, etc. Furthermore in my process mixed ni trio and sulfuric acids are used and a nitric acid of a low strength is used.

A further object is to provide a process of this character which is cheaper and moripractical than previous processes of a similar nature.

A further object is of this character in which spontaneously at the ordinary or a relatively low temperaturc,-that is to say, below 40 'hich proceeds smoothly and regu larly until. practically all of the nitric acid has been used up and only a trace thereof remains in the residual weak sulfuric acid with which it is mixed in carrying out the roccss, and in which the sulfuric acid may be readily recovered for concentration and fortification for further use.

A further object is to use mined acids containing such a percentage of water as not to have the reaction proceed too violently.

While my inventlon is capable of being carried out in many different ways, for the purpose of illustration, I shall describe only one Way of accomplishing the same hereinafter.

For example, I may proceed as follows: A quantity of mixed nitric and sulfuric acids is made, containing the following proportions 5 9. kilograms of sulfuric acid, 66

The object to provide a process the reaction starts portion of 1%., and 253 kilograms of nitric acid, 26 136., specific gravity 1.22 The mixed acid is introduced into a container, which may be provided with any desired type of stirring device. Thereupon about 1 kilogram of isoborneol is added to the mixed acid. Only a small amount of the iso-borncol is added in order to avoid having the reaction proceed too violently. If the reaction proceeds too violently the undesirable products, such as resinous compounds and camphoric acid will be formed, and the compounds will become subjected to such violent cbullition that they cannot be retained in the vessel. When the temperature has risen to above 40 C. indicating that the reaction has begun, which will usually be after about 15 minutes, additional iso-borneol is added gradually, and with caution taking care that the temperature of the mass remains between 35 and i0" C. during the reaction, continuing the addition until the entire amount of isoborneol added equals 154 kilograms. The supermitant liquid, which contains the cam phor in the form of a loose addition compound with N 0 is then decanted and run into water, where the camphor precipitates as a solid, and is then washed, centrifuged, dried and purified. In this way a substan' tially theoretical yield is obtained.

While I have described my invention above in detail, I wish it to be understood that many changes may be made therein without departing from the spirit of my in vention.

I claim.

1. The process which comprises oxidizing iso-borneol into camphor by the application of mixed nitric and sulfuric acids.

2. The process which comprises oxidizing iso-borneol into camphor by the a plication of mixed nitric and sulfuric aci s in such proportions as to start the reaction spontaneously.

3. The process which comprises oxidizing iso-borneol into camphor by the application of mixed nitric and sulfuric acids in the prosubstantially 57% sulfuric acid 66 B. and 43% ni ric acid 26 B.

Al Thdprocess w ich comprises oxidizing iso-borueol into camphor by the appli ation of mixed nitric and sulfuric acids, the tempcrature during at least the first part of the reaction being maintained at -10 (I or less.

5. The process uhich comprises oxidizing iso-horneol into camphor by the application of mixed nitric and sulfuric acids in such proportions as to start the reaction spontancously, the temperature during at least the first part of the reaction being maintallied at about 4W or less.

(5. The process which comprises oxidizing iso-borneol into ramphor by the application of mixed nitric and sulfuric acids in the proportion of substantially 57in, sulfuric a id 66" B6. and 431, nitric acid 26 lid, the temperature during at least the first part of the reaction being mainta ned at about in or less.

T. The process which comprises oxidizing iso-borncol into camphor by the application of mixed nitric and .--ulfuri a ids, the temperature during at least the tint part of the reaction being maintained. at approxi mately 3-) t.

is. The process which coinprisw oxidizing isobormol into camphor by the application of mixed nitric and sulfuric acids in such proportions as to start the reaction spontaneonsly, the temperature during at least the first part of the reaction being maintained at approximately 35 (F.

9. The process which comprises oxidizing iso-borneol into camphcr by the application of mixed nitric and sulliuric acids in the proportion of substantially 57'}? sulfuric acid 66 Be. and 43V nitric acid 26" 1%.. the temperature during at least the first part of the reaction being maintained at approximately 35 C.

10. The process which comprises oxidizing is0l)orneol into camphor by the application of mixed nitric and sulfuric acids, the isoborneol being added to the mixed acid initially in a small quantity until the reaction is started, and thereafter adding further quantities gradually.

11. The process which comprises oxidiz ing iso-borncol into camphor by the application of mixed nitric and sulfuric acids in such. propoi'tions as to start the reaction spontaneously, the iso-borneol being added to the mixed acid initially in a smalluantity until the reaction is started, and t erea fter adding further quantities gradually.

12. The process which comprises oxidizing isoborneol into camphor by the application of mixed nitric and sulfuric acids in the proportion of substantially 57% sulfuric acid 66 B. and 43% nitric acid 26" 136., the iso-borneol being added to the mixed acid initially in a small quantity until the reaction is started, and thereafter adding further quantities gradually.

135. The process which comprises oxidiz- 66 big iso-horueol into cumphor by the application of mixed nitric and sulfuric acids, the temperature at least during the first part of the reaction being maintained at 40" (I. or less. the iso-borncol being added to the mixed arid initially in a small quantity until the reaction is started, and thereafter adding further quantities gradually.

14. The process which comprises oxidiz ing iso-horncol into camphor h the application of mixed nitric and sul uric acids in such proportions as to start the reaction spontaneously, the temperature at least during the first part of the reaction being maiutained at 40 or less, the iso-horneol being added to the mixed acid initially in a small quantity until the reaction is started, and thereafter inlding further quantities gradually.

1.3. The process which comprises oxidizing isdhorneol into camphor by the application of'mixcd nitric and sulfuric acids in the proportion of substantially 57% sulfuric acid 66 B6. and 43% nitric acid 26 lie, the temperature at least during the first part of the reaction being maintained at 40 C. or less, the iso-borneol being added to the mixed acid initially in a small quantity until the reaction is started, and thereafter adding further quantities gradually.

16. The process which com )rises oxidizing iso-borneol into camphor by the application of mixed nitric and sulfuric acids, the temperature during at least the first part of the reaction being maintained at approximately 35 C, the iso-borneol bein added to the mixed acid initially in a. sma l quantity until the reaction is started, and thereafter adding further quantities gradually.

17. The process which comprises oxidizing iso-borneol into camphor by the application of mixed nitric and sulfuric acids in such proportions as to start the reaction spontaneously, the temperature during a. least the first part of the reaction being maintained at approximately 35 (3., the isoborneol being added to the mixed acid initially in a small quantity until the reaction is started, and thereafter adding further quantities gradually.

18. he, process which com )rises oxidiz ing iso-borneol into camphor by the application of mixed nitric and sulfuric acids in the proportion of substantially 57% sulfuric acid 66 B6. and 43% nitric acid 26 1313., the temperature during at least the first part of the reaction being maintained at approximately'35" (l, the iso-borneol being added to the mixed acid initially in a small quantity until the reaction is started, and thereafter adding further quantities gradually.

19. The process of oxidizing iso-borneol into camphor in such a manner as to avoid the production of resinous compounds which comprises inducing a reaction between mixed nitrlc and sulfuric acids and iso-borneol under controlled temperature conditions.

20. The process of oxidizing iso-borneol into camphor which comprises bringing together iao-borneol and mixed nitric and sulhave hereunto set m furic acids at such a rate as to avoid violent obullition. 10

In testimony that I claim the foregoing hand. ROL ND L. ANDREAU. Witnesses:

R. E. S'rmoumnn, WILLAKD T. WHITE.