Ward appeals from the Board of Appeals' affirmance of the rejection of his application1 for a patent on a "New Series of Carboxylic Acid Esters of 5-Nitro-2-Furyl Alkylidene Hydroxyalkyl Semicarbazones."

All of the claims are directed to compounds, useful as chemotherapeutics, which are derived from their corresponding alcohols.

"1. A carboxylic acid ester of a 5-nitro-2-furyl alkylidene hydroxyalkyl semicarbazone represented by the formula:

NOTE: OPINION CONTAINING TABLE OR OTHER DATA THAT IS NOT VIEWABLE

wherein

n represents an integer from O-1, and R and R₁ represent dissimilar groups selected from the class consisting of hydrogen and (lower) alkanoyloxy (lower) alkyl."

  Stillman   2,416,234   February 18, 1949.
  Ward       2,656,350   October  20, 1953.

Hayes et al., J. Amer. Chem. Soc., Vol. 77 (1955), page 2282.

Cheronis et al., Semi-micro Qualitative Analysis, Crowell Publishing Company, New York, 1947, pages 179, 180.

Stillman and Ward disclose 5-nitro-2-furaldehyde semicarbazones substituted in the 2 or 4 position by a hydroxyalkyl group. Hayes et al. disclose beta-(5-nitro-2-furyl) acrolein 2-(hydroxyalkyl) semicarbazones. Those compounds differ from the compounds being claimed only in one respect, namely, the hydroxyalkyl substituents of the prior art compounds have been esterified. Thus the claims are drawn to the ester derivatives of prior art alcohols.

Cheronis et al. disclose that it is customary in the identification of alcohols to form simple2 esters thereof. The claimed esters were held to be obvious by the examiner in view of the corresponding alcohols and the fact that simple esters are customarily formed in the identification of alcohols.

Ward filed two affidavits to show that the claimed esters possess properties which would not be expected from the corresponding alcohols of the prior art. We find it unnecessary to discuss the first affidavit since, the second affidavit, that of O'Connor, establishes that the esters are effective in combatting coccidiosis in chickens whereas the corresponding alcohols are devoid of any such activity.

The board agreed with the examiner that since simple esters are customarily prepared to identify the corresponding alcohol, the claimed simple esters were obvious from the prior art alcohols.

"* * * Appellant also refers to the Hayes and O'Connor affidavits as showing a difference in kind in the esters over the alcohols; however, as to the utility of the affidavits, we agree with the Examiner that they are not convincing that the esters sought to be patented would be unobvious, as the claims are not limited to such utility of the ester compound but are directed to the ester compounds per se. * * * (Emphasis supplied).

* * * * * *

"* * * We, therefore, do not believe that ascertaining that the ester formed is more effective in certain unclaimed uses makes the esters any less obvious. * * *"

The examiner, in his Examiner's Answer before the board, elaborated on that point a bit more:

"* * * The rejected claims are not drawn to the contended invention involving the use of the obtained compounds. Insofar as the invention as contended by the applicant does involve the use of the alkanoic esters now claimed for a certain purpose, the invention if properly claimed would belong to a different statutory class of invention."

The difficulty with that reasoning is that claims to chemical compounds are drawn to more than structural formulae. They define the compounds themselves and compounds possess properties which must be considered along with the formulae.

Here the esters might appear to be obvious in terms of the concept of their structure but that is only half the game. There remains the consideration of the properties of the esters. Ward prepared the claimed esters and, as substantiated by the O'Connor affidavit, discovered that they have the property of being effective in combatting coccidiosis in chickens whereas the corresponding alcohols are totally ineffective. That unexpected property cannot be ignored in the determination of obviousness of the claimed esters as substances and not as structural formulae.3 Indeed, here we find that evidence persuasive of unobviousness and, therefore, are obliged to reverse.

Reversed.