Obviousness of Chemical Processes

• Chemical process claims are the same as other method claims as to claim-drafting techniques.
  • Robert C. Faber provides a good discussion of subject in his PLI treatise: “Faber on Mechanics of Patent Claim Drafting” §4:7 Chemical Processes.^†

Old Techniques /New Compounds

• Chemical processes may be nonobvious, albeit using old standard techniques, if the processes:

(1) Uses a novel and unobvious starting material;

or

(2) Produces a novel and nonobvious chemical product.

• The Court of Appeals for the Federal Circuit (CAFC) explain the law in In re Ochiai, 71 F.3d 1561 (Fed. Cir., 1995).^ǂ The ruling has stood the test of time.
• See also, MPEP §2106.01 – Novel, an Obvious Starting Material or End Product

In re Ochiai 71 F.3d 1561 (CAFC, 1995)

US Patent No. 5,583,216: “Method for the Manufacture of Cephems” Takeda

• Ochiai’s claims directed to synthesizing cephalosporin analogs were patentable, even though they used “standard” acylation reactions, because the starting materials and the final product, themselves were novel and non-obvious.

Claim 1: A process for preparing a cephem compound^†† of the formula:

wherein R³ is hydrogen or methoxy, R⁴ is hydrogen or a residue of a nucleophilic compound, R⁵ is hydroxyl or a protected hydroxyl, and R⁸ is hydrogen or a halogen, or a pharmaceutically acceptable salt or ester thereof, which comprises introducing an acyl group of the formula:

wherein R⁵ and R⁸ are as defined above into the amino group of the molecule of the formula:

wherein R³ and R⁴ are as defined above or a salt or ester thereof.

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• The Court, in Ochiai, held that there is no per se rule that a process claim is obvious if the prior art references disclose the same general process using “similar” starting materials.
• Importantly, the examiner conceded the total absence from the prior art of both the acid used and the cephem made in the process.
• The court found that Ochiai’s process was nonobvious “having compared Ochiai’s claims, limited as they are to the use of a particular nonobvious starting material for making a particular non-obvious and product, to the prior art of record.”

All claim limitations must be considered

• The MPEP reminds us that “All the claim limitations must be considered … in determining the obviousness of a process or method claim” (Emphasis in MPEP, citing MPEP §2143.03). Process claims include, not only the element of the process steps, but also include the elements of the compounds themselves.  Even though the steps may be known, a claim may be non-obvious if the starting materials or the product itself is novel and non-obvious.

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^† “Faber on Mechanics of Patent Claim Drafting” §4:7 Chemical Processes (Faber Rel. #3, 11/16) (7^th Edition) Robert C. Faber, Practicing Law Institute, New York City, ISBN Number: 9781402424267

^ǂ An October 2017 Key Cite and Shepard’s Citation search indicated that In re Ochiai is still good.

^†† Ochiai’s U.S. Patent No. 4,298,606 covers the cephem compound resulting from the process.