Obviousness

The user is asking for an obviousness analysis of US patent 8026378 under 35 U.S.C. § 103, based on the provided patent text and previously generated sections. I need to identify combinations of prior art references that would render the claims obvious, and explain the motivation for a person having ordinary skill in the art (PHOSITA) to combine them.

The priority date of US8026378 is November 22, 2005. All cited prior art must have a publication date prior to this date.

Review of Independent Claims:

• Claim 1: A compound having the formula (8), (9a), or (9b), where R6 is hydrogen or a C1-C10 linear or branched alkyl, and V is a 2,3-dihydroxypropyloxy group, or a protected glycerol group (1,3-dioxolane or 1,3-dioxane with R4/R5, or a hydroxyl derivative). Essentially, these are glyceryl ether compounds derived from epoxidized fatty acid esters or triglycerides, where the glycerol moiety can be unprotected or protected (as a ketal/acetal).
• Claim 2: A method for preparing a compound of claim 1, comprising:
  • a) providing glycerol or a protected glycerol of formula (3) (ketal/acetal of glycerol with R4/R5).
  • b) providing an epoxidized triglyceride or an epoxidized unsaturated fatty acid ester (fatty acid fragment C8-C24, alcohol fragment C1-C12 monohydric alcohol).
  • c) effecting a reaction between (a) and (b) in the presence of an acid or base catalyst.
• Claim 3: The method of claim 2, further comprising:
  • d) converting the carboxyl ester group to a free carboxyl group, a carboxylic salt, or an amide.

Key Prior Art References identified and their relevance (with dates confirmed prior to Nov 22, 2005):

1. US5442082A (Henkel KGaA, 1995-08-15): Discloses "alkoxylated compounds produced from epoxidized carboxylic acid derivatives, preferably epoxidized fatty acid esters, with hydroxyl compounds in the presence of acid catalysts." This teaches the reaction of epoxidized fatty acid esters with hydroxyl compounds using acid catalysts, directly addressing elements of Claims 1 and 2.
2. US20040077904A1 (Kao Corporation, 2004-04-22): Discloses a "production process for glycidyl ether adduct and catalyst used for the process." It teaches reacting a glycidyl ether with an alcohol (including polyvalent alcohols like glycerin) in the presence of a catalyst (acid or base). This is relevant for using glycerol as a reactant and for the types of catalysts.
3. Karabina, E. And Borredon, M.E, "Synthesis of Hydroxyethers from Glycerol and Fatty Chains Epoxyalkanes in the Absence of Organic Solvent", Synthetic Communications (1994): Directly teaches the synthesis of hydroxyethers from glycerol and epoxyalkanes. This supports the reaction of glycerol with epoxides to form glyceryl ethers.
4. Ono, et al., "Preparation, Surface-Active Properties and Acid Decomposition Profiles of a New 'Soap' Bearing a 1,3-Dioxolane Ring." JAOCS (1993): Shows the use of a 1,3-dioxolane ring (a protected glycerol moiety, corresponding to V in Claim 1 and part of formula (3) in Claim 2) in a surfactant.
5. Muturi, et al., "Epoxidized Vegetable Oils as Reactive Diluents I. Comparision of Vernonia, Epoxidized Soybean and Epoxidized Linseed Oils." Progress in Organic Coatings (1994): Demonstrates knowledge of epoxidized vegetable oils (triglycerides) as starting materials.
6. Du, et al., "Catalytic Epoxidation of Methyl Linoleate." JAOCS (2004): Shows the epoxidation of fatty acid methyl esters.
7. Wedmid, et al., "Long-Chain Stereomeric 2-Alkyl-4-methoxycarbonyl-1,3-dioxolanes in Glycerol Acetal Synthesis." J. Org. Chem. (1977): Shows the synthesis of 1,3-dioxolanes from glycerol.
8. JPH04217972A (Mitsuo Okahara, 1992-08-07): Discusses "New carboxylic acid salt derivative and decomposable surfactant made thereof," indicating that carboxylic acid salts derived from surfactants were known.
9. EP2301941B1 (published 2013-06-19, but priority of an earlier patent): EP2301941B1 cites US20040077904A1, which is prior art. Also, Google Patents provides "Process for the production of a dioxolane compound from crude glycerol" (EP2760850A1) showing that "The preparation of a dioxolane compound by way of reacting glycerol and a ketone or an aldehyde is generally known".

Obviousness Analysis under 35 U.S.C. § 103

A person having ordinary skill in the art (PHOSITA) in the field of organic chemistry and surfactant development, as of the priority date of November 22, 2005, would have possessed a strong motivation to develop new surfactants from renewable and inexpensive raw materials. This motivation is explicitly stated in the background of US8026378: "Therefore, well-performing surfactants that utilize abundant, renewable, and inexpensive raw materials and simpler chemical synthesis methods are highly desired."

1. Obviousness of Claim 1 (The Compound)

Claim 1 describes specific glyceryl ether compounds, which are adducts of epoxidized fatty acid esters or triglycerides with glycerol, potentially in a protected (ketal/acetal) form.

• Combination of US5442082A and US20040077904A1:

  • US5442082A teaches the fundamental concept of producing "alkoxylated compounds from epoxidized carboxylic acid derivatives, preferably epoxidized fatty acid esters, with hydroxyl compounds in the presence of acid catalysts." This directly provides the structural basis for a compound where a fatty acid ester is linked via an ether bond to a hydroxyl compound.
  • US20040077904A1 teaches that glycerin (glycerol) is a suitable polyvalent alcohol for reacting with epoxides to form glycidyl ether adducts.
  • Motivation to Combine: A PHOSITA, aiming to create a new surfactant from renewable resources, would be motivated to combine the teachings of US5442082A (using epoxidized fatty acid esters) with the known reactivity of glycerol as a hydroxyl compound (US20040077904A1, Karabina & Borredon 1994) to form an ether linkage. This combination directly leads to the glyceryl ether compounds of Claim 1 where V is a deprotected 2,3-dihydroxypropyloxy group. The specific chain lengths of the fatty acid fragment (C8-C24) and the alcohol fragment (C1-C12) are routine variations within the scope of fatty acid chemistry and surfactant design.

• Addressing the "Protected Glycerol" (V as a dioxolane/dioxane):

  • Ono et al. (1993) explicitly describes a "new 'Soap' Bearing a 1,3-Dioxolane Ring," demonstrating that surfactants containing a protected glycerol moiety were known in the art.
  • The patent US8026378 itself states that "Many ketals and acetals of formula (3), and methods for their preparation from glycerol, are known in the art." This is an admission of prior art regarding protected glycerol. Wedmid et al. (1977) also details the synthesis of 1,3-dioxolanes from glycerol.
  • Motivation to use protected glycerol: US8026378 provides the motivation within its own text: "Reaction of unprotected glycerol with NAO epoxides... typically results in the formation of higher quantities of various byproducts... It is preferred, therefore, that epoxides be reacted with 1,2-ketals of glycerol." A PHOSITA would be motivated to use protected glycerol (e.g., a ketal or acetal) to improve reaction selectivity and minimize byproduct formation, leading to a purer and more efficient synthesis of the desired glyceryl ether surfactant. Therefore, substituting unprotected glycerol with a protected form, known in surfactant chemistry, would have been obvious.

2. Obviousness of Claim 2 (The Method)

Claim 2 describes a method for preparing the compounds of Claim 1 by reacting glycerol (or protected glycerol) with an epoxidized fatty acid ester or triglyceride in the presence of an acid or base catalyst.

• Elements (a) and (b) – Reactants:

  • Glycerol or protected glycerol (a): Glycerol is a fundamental chemical, and its protected forms (ketals/acetals) are known, as admitted by US8026378. Ono et al. (1993) shows 1,3-dioxolane containing surfactants.
  • Epoxidized triglyceride or epoxidized unsaturated fatty acid ester (b): US5442082A teaches the use of "epoxidized carboxylic acid derivatives, preferably epoxidized fatty acid esters." Muturi et al. (1994) discusses "Epoxidized Vegetable Oils" (triglycerides). Du et al. (2004) teaches the epoxidation of methyl linoleate, a fatty acid methyl ester.
  • Motivation for (a) and (b): The desire for "abundant, renewable, and inexpensive raw materials" (US8026378) would lead a PHOSITA to combine readily available glycerol (or its protected forms for improved selectivity) with epoxidized fatty acid derivatives, which are also bio-based and well-known (Muturi et al. 1994, Du et al. 2004).

• Element (c) – Reaction and Catalyst:

  • Reaction between (a) and (b): The reaction of epoxides with alcohols (including glycerol) to form ether linkages is well-established. US5442082A explicitly teaches this type of reaction. Karabina & Borredon (1994) also teach the synthesis of hydroxyethers from glycerol and epoxyalkanes.
  • Acid or base catalyst: US5442082A specifies "acid catalysts." US20040077904A1 discusses both acid and base catalysts for similar epoxide-alcohol reactions. US8026378 itself admits that "Catalysts for reacting epoxides... with glycerol or with a compound of formula (3) can include various acids, and other catalysts known in the art."
  • Motivation for (c): The choice of acid or base catalysts for epoxide opening reactions with alcohols is a matter of routine optimization for a PHOSITA, based on known chemical principles and guided by references such as US5442082A and US20040077904A1.

3. Obviousness of Claim 3 (Converting the Carboxyl Ester Group)

Claim 3 describes the further step of converting the carboxyl ester group of the compound from Claim 1 to a free carboxyl group, a carboxylic salt, or an amide.

• Prior Art: Saponification (hydrolysis of esters to carboxylic acids or their salts) and amidation of esters are fundamental, well-known chemical reactions in organic chemistry, routinely taught and practiced. JPH04217972A (1992) shows knowledge of carboxylic acid salt derivatives as surfactants.
• Motivation: US8026378 itself explicitly states the utility and motivation for this conversion: "The carboxyl group in the ether adducts of glycerol and the hydroxylated fatty acid esters can optionally be saponified to furnish a salt... Furthermore, the carboxyl group can be amidated..." and "Such secondary derivatives resulting from the chemical modifications at the carboxyl group are useful ionic surfactants that work well in hard water." A PHOSITA, understanding the need for surfactants that perform well in hard water, would be routinely motivated to apply these standard chemical transformations to modify the properties of the initially formed ester compounds.

Conclusion:

Based on the cited prior art and the explicit admissions and motivations within US patent 8026378, a person having ordinary skill in the art would have found the claimed compounds and methods obvious as of the priority date. The core chemical transformations, the use of glycerol and protected glycerol, epoxidized fatty acid derivatives as starting materials, appropriate catalysts, and the subsequent modification of ester groups, were all known and well-motivated in the art of surfactant chemistry, particularly for developing renewable and high-performing surfactants.