
    343 F. 2d 490; 145 USPQ 213
    In re Siegfried Gottfried and Lily Baxendale
    (No. 7376)
    United States Court of Customs and Patent Appeals,
    April 15, 1965
    
      John T. Miller (A. Ponalc, of counsel) for appellants.
    
      Clarence W. Moore (J. F. Nakamura, of counsel) for the Commissioner of of Patents.
    [Oral argument March 4, 1965, by Mr. Miller and Mr. Nakamura]
    Before Worley, Chief Judge, and Rich, Martin, and Almond, Jr., Associate Judges.
   Almond, Judge,

delivered the opinion of the court:

This appeal is from a decision of the Board of Appeals affirming the examiner’s rejection of process claims 1-5 in appellants’ application. The invention is a method of converting 18/3-glyeyrrhetinic acid to 18a-glycyrrhetinic acid.

Claim 1 reproduced below is illustrative:

A process for the production of 18a-glycyrrhetinic acid, wherein 18/3-glycyr-rhetinic acid is heated with an alkali metal hydroxide in a medium selected from the group consisting of an alcoholic and an aqueous-alcoholic medium.

The reference relied upon by the examiner is Beaton, J. Chem. Soc. pp. 3126-29 (1955). Beaton contains the following disclosure:

Formula I is 18/?-glycyrrhetinic acid when both It and It' are hydrogen. Formula II is 18«-glycyrrhetinic acid when both It and It' are hydrogen. It can be seen that the a and /3 forms of the acid differ from each other only in the position of the hydrogen atom on the 18-carbon atom. Appellants’ process is represented by the above equation when both 11 and IT are H and when the reaction medium contains a metal hydroxide (OH-). Beaton does not specifically disclose the claimed reaction. The following portion of Beaton is the most significant :

Prolonged treatment of methyl giycynTietate with concentrated alkali gives an acid different from, and isomeric with, glycyrrhetic acid [18/3-glycyrrhetinic]. The isomeric acid is also obtained by heating a solution of glycyrrhetic acid in acetic acid containing concentrated hydrochloric acid.
lSa-Glycyrrhetiv Add (II; R=R'=H).— (a) A mixture of methyl glycyrrlie-tate (I; R=H.R'=Me) (lOg.) and potassium hydroxide (400g.) in water (200c.c.) and ethanol (ISOOc.c.) was refluxed for 120 hr. The solution was diluted with water (2 1.), then acidified with concentrated hydrochloric acid, and the precipitated solid collected. Repeated crystallisation from chloroform-methanol yielded lSa-ylyeyniietie add * * *.

The examiner rejected the claims as obvious in view of Beaton, reasoning as follows:

It is considered that the instantly claimed treatment of glycyrrhetic acid is rendered obvious by the reference treatment of the corresponding methyl ester, since for purposes of isomerization the methyl ester is suggestive of the free acid, the isomerization being around the 18-carbon position.

The above language indicates that the statutory basis of the rejection was 35 USC 103. The board affirmed the examiner, stating: “We agree in general with the Examiner’s position * * *.” However, the board then went on to say that appellants’ process was inherent in the Beaton disclosure, stating:

Although the stated starting material in Beaton et al. is the methyl ester of beta glycyrrhetinic acid it is quite apparent from the disclosure that this ester, in the alkaline medium indicated above, first hydrolyzes to the corresponding beta glycyrrhetinic acid, which latter must then isomerize during prolonged treatment to produce alpha glycyrrhetinic acid fully in accordance with the terms of appellants’ claims. * * *

Appellants claim that the board’s language is indicative of a rejection under 35 USC 102. The solicitor maintains that the rejection is based only on 35 USC 103. We feel that the decision can be affirmed on the basis of obviousness and thus will not consider the question of a “102 rejection.”

The solicitor’s position is that it would be obvious to substitute the 18/3-acid for 18/3-ester in the Beaton isomerization of 18,8-ester to 18a-acid. He points out that isomerization occurs at the 18-carbon which is removed from the acid or ester group and that it is obvious that isomerization would occur in the presence of a base regardless of the particular IT. A further suggestion would come from the equation in Beaton set forth above. Beaton gives only two possibilities for R', H and CH3. When R' in both formulas is H, and basic reaction medium is used, the claimed invention is depicted by the Beaton equation above. Appellants argue that the equation cannot be considered generic but that it was only meant by Beaton to cover the reactions actually carried out by him. Even if this is true, however, the equation encompasses only a rather limited number of reactions (when R and E' are limited to H and methyl). Therefore, we think that inspection of the equation by one of ordinary skill in the art would readily suggest the isomerization of the 18/3-acid in basic medium even though the reaction is not fully disclosed by the equation.

Although we do not necessarity agree with the board that the claimed isomerization inherently occurs during the Beaton conversion of the 18/3-methyl ester to the 18a-acid in basic medium, we think that such a reaction mechanism is quite likely. Beaton states that hydrolysis of the 18/3-methyl ester in 3% potassium hydroxide gave 5% 18/3-acid after two hours, the remainder being “unchanged ester.” Since prolonged treatment in a stronger basic solution results in conversion of the 18/3-ester to the 18«-acid, one could expect that conversion of the 18/3-ester to the 18/3-acid occurs first and that isomerization of 18/3-acid as claimed is the second step of the reaction. Thus, the claimed reaction would also be suggested by a consideration of the reaction mechanism.

The Beaton disclosure, considered in its entirety, contains a teaching which we think would make it obvious, within the meaning of 35 USC 103, to isomerize 18/3-acid to 18a-acid in a basic medium.

Appellants point to the fact that in the two examples in their specification the yields of 18a-acid from 18/3-acid were 55% and 77% compared with Beaton's yield of 38%: in going from the 18/3-ester to the 18a-acid. The reaction conditions differed in all three reactions, and of course appellants’ starting material is different. We cannot agree that the differences in yield between appellants’ examples and the Beaton example are persuasive of unobviousness. The differences might well be due to the different reaction conditions. Clearly the optimum reaction time and base concentration are not appellants’ invention. If the improved yields do in fact result from the direct isomerization, we do not feel that when weighed with the evidence of obviousness set forth above, the improvement is so great as to result in a finding of unobviousness.

For the foregoing reasons, we affirm the board’s decision.

Smith, J., concurs in the result. 
      
       Serial No. 44,258, filed July 21, 1960 for “Process for the Production of 18a Glycyr-rhetinic Acid.”
     
      
       The number 18 has been added to identify the hydrogen on the 18-carbon atom.
     