Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
DETAILED ACTION
Claims 1, 6, 8, 9, 11, and 12 of R. Park et al., US 17/906,476 (Mar. 5, 2021) are pending and under examination. Claims 1, 6, 8, 9, 11, and 12 are rejected.
Claim Rejections - 35 USC § 103
The following is a quotation of AIA 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103(a) are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1, 6, 8, 9, 11, and 12 are rejected under AIA 35 U.S.C. 103 as being unpatentable over K. Butakoff et al., 15 Polyhedron, 489-499 (1996) (“Butakoff”) in view of D. Crowther et al., WO 2018/067289 (2018) (“Crowther”) and N. G. Anderson, PRACTICAL PROCESS & RESEARCH DEVELOPMENT, 27-52, 81-111, 113-143 (2000) (“Anderson”) and/or Y. Hayashi, 7 Chemical Science, 866-880 (2016) (“Hayashi”).
The Claimed Invention
Claim 1 recites as follows:
1. A process for preparing a transition metal compound represented by any one of Formulae 1-1 to 1-24, which comprises
(1) dissolving a compound represented by any one of Formulae 2-1 to 2-6, in a solvent;
(2) adding a compound represented by Formula 4 to the solution obtained in step (1) and reacting it under stirring; and
(3) adding a compound represented by any one Formulae 3-1 to 3-9 to the solution obtained in step (2) and reacting it under stirring:
[Formulae 1-1 to 1-24, structure omitted here]
[Formulae 2-1 to 2-6, structures omitted here]
[Formulae 3-1 to 3-9, structures omitted here ]
[Formula 4]
MX4
in Formula 4, M is Zirconium (Zr), or Hafnium (Hf), and X is Cl.
Claim 1 is summarized schematically by the Examiner below.
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The specification discloses two working examples. Working Example 1 is summarized by the Examiner below.
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Specification at page 15, lines 271-283. Specification working Example 2 is essentially the same as working Example 1, except in Example 2, HfCl4 replaces the ZrCl4 of Example 1, to give the respective hafnium compound. Specification at page 15, lines 284-296.
K. Butakoff et al., 15 Polyhedron, 489-499 (1996) (“Butakoff”)
Butakoff teaches that the current interest in the synthesis and study of new metallocene derivatives of the group 4 metals derives in the main part from their capacity to act as Ziegler-Natta alkene polymerization catalysts or catalyst precursors. Butakoff at page 489, col. 1.
Butakoff teaches synthesis of [Zr2(-Cp=)2Cl4(μ-Cl)2] (1) (isolated as a yellow solid) as follows:
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Butakoff at page 497, col. 1. Note that Butakoff defines Cp= as the tetramethylcyclopentadienyl but-4-ene ligand C5Me4CH2CH2CH=CH2. Butakoff at page 489, col. 2.
Butakoff then employs compound 1 (prepared as above) in the synthesis of [Zr(-Cp=)(-C5Me5)Cl2], compound 4, as follows.
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Butakoff at page 497, col. 2.
Differences between Butakoff and Claim 1
Butakoff differs from claim 1 essentially only in that the cyclopentadienyl anion reactants and products have different R groups. For example, Butakoff differs from claim 1 in that Butakoff’s initial cyclopentadienyl anion reactant (i.e., LiCp=) comprises a different substitution pattern than claim 1 Formulae 2-1 to 2-6; for example, compare Butakoff’s LiCp= with Formula 2-1.
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Butakoff further differs from claim 1 in that Butakoff’s second added cyclopentadienyl anion reactant (i.e., Li[C5Me5]) also comprises a different substitution pattern than claim 1 Formulae 3-1 to 3-9; for example, compare Butakoff’s Li[C5Me5] with Formula 3-1.
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Butakoff further does not specifically teach the claim 1, step 3 concept of directly using the solution of [Zr2(-Cp=)2Cl4(μ-Cl)2] (1) obtained in a further reaction. Rather Butakoff first isolates the [Zr2(-Cp=)2Cl4(μ-Cl)2] (1) as a yellow solid before taking it to the next step.
D. Crowther et al., WO 2018/067289 (2018) (“Crowther”)
Crowther is cited here as motivating one of ordinary skill to synthesize and explore synthetic optimization of the metallocenes CAS No. 183541-62-0 and CAS No. 2222102-04-5 in view of Crowther’s teaching of their catalytic utility in olefin polymerization. These are the same compounds prepared in the instant specification working examples 1 and 2.
Crowther teaches that polyolefins are typically prepared with a catalyst that polymerizes olefin monomers. Indeed, olefin polymerization catalysts are in great demand in industry. Crowther at page 1, lines 17-21. Crowther teaches that there is interest in finding new catalyst systems that increase the commercial usefulness of the catalyst and provide for production of polyolefins, such as polyethylenes, having improved properties over known polyolefin compositions. Crowther at page 1, lines 17-21.
Crowther teaches a catalyst compound is represented by Formula (I), where M is a group 4 metal and X may be a halide. Crowther at page 3, [0010]. Crowther teaches a process for producing a polyolefin composition comprises contacting one or more olefins with a catalyst system comprising: (a) the catalyst compound represented by Formula (I); (b) a bridged or unbridged metallocene catalyst 20 compound other than the catalyst compound represented by Formula (I), and (c) activator. Crowther at page 3, [0012]. That is, Crowther teaches a catalyst system includes the catalyst represented by Formula (I) in addition to a second catalyst compound that is a bridged or unbridged metallocene catalyst compound other than the catalyst compound represented by Formula (I). Crowther at page 20, [0055].
With respect to the second metal catalyst, Crowther teaches that:
The second metallocene catalyst compound may be an unbridged metallocene catalyst compound represented by the formula: CpACpBM'X'n. Each CpA and CpB is independently selected from the group consisting of cyclopentadienyl ligands. One or both CpA and CpB may contain heteroatoms. One or both CpA and CpB may be substituted by one or more R" groups. M' is selected from the group consisting of Groups 3 through 12 atoms and lanthanide Group atoms. X' is an anionic leaving group. n is 0 or an integer from 1 to 4.
Crowther at page 20, [0056]. Crowther teaches a number of suitable example species of the second metal catalyst. Crowther at page 21, [0057]. For example, Crowther teaches that the second catalyst may be (n-propylcyclopentadienyl, pentamethylcyclopentadienyl)zirconium dichloride (CAS No. 183541-62-0) or (n-propylcyclopentadienyl, pentamethylcyclopentadienyl)-hafnium dichloride (CAS No. 2222102-04-5), which two metallocenes have the following structures:
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Crowther at page 21, [0057]; for indexed CAS number see, CAS Abstract and Indexed Compounds, D. Crowther et al., WO 2018/067289 (2018).
Crowther therefore motivates one of ordinary skill to synthesize and explore synthetic optimization of metallocenes CAS No. 183541-62-0 and CAS No. 2222102-04-5 in view of their catalytic utility.
N. G. Anderson, PRACTICAL PROCESS & RESEARCH DEVELOPMENT, 27-52, 81-111, 113-143 (2000) (“Anderson”)
Anderson teaches that chemists have developed generally applicable paradigms for synthetic-process optimization; for example, use of convergent synthesis, telescopic workups, solvent and protecting group selection, and minimizing the number of reaction steps. Anderson at pages 27-52. Anderson teaches that telescopic workup can be cost effective. See Anderson at page 29, Table 2.1. In this regard, Anderson teaches that isolating intermediates has many potential disadvantages; for example, isolation is usually costly and invariably leads to some loss of valuable material and that on a manufacturing scale, isolating intermediates and API requires about 50% of personnel time and about 75% of equipment financial outlay and that this additional handling required increases both exposure of operators to pharmacologically potent materials and opportunities for contamination of batches and loss of valuable product. Anderson at page 34. Anderson teaches that isolations are avoided by telescoping, also known as concatenation or through-processes, is the process of carrying the product of a reaction without isolation into the next step and that appropriate telescoping can greatly increase overall yields. Anderson at page 34. Anderson further teaches that unless significant purification or other benefits are realized by isolating intermediates, telescoping is incorporated as part of cost-effective routes. Anderson at page 34.
Anderson teaches that solvents are selected to increase reaction rates, to increase the reproducibility and ease of running reactions, and to ensure that the desired quality and yield of product is reached and that other important considerations are to decrease waste and allow for efficient solvent recovery and reuse. Anderson at page 81. Anderson teaches routine methods of solvent selection in organic synthesis. See Anderson at page 83 et seq. In Table 4.3, Anderson lists characteristics of many solvents that are useful for scale-up operations. Anderson at pages 85-88. Anderson Table 1 lists both ethyl acetate (EtOAc) and dimethyl formamide (DMF). Anderson further teaches that recovery and reuse of solvents may have great financial impact for manufacturing operations. Anderson at page 102. Anderson thus clearly teaches that solvent selection is a result-effective variable. MPEP § 2144.05(II)(B).
Y. Hayashi, 7 Chemical Science, 866-880 (2016) (“Hayashi”)
Hayashi teaches that the one-pot synthesis of a target molecule in the same reaction vessel is widely considered to be an efficient approach in synthetic organic chemistry. Hayashi at Abstract. Hayashi teaches that “telescoped”, “one pot” reactions, where intermediates are not isolated improve reaction economy (reduces expense) because intermediate workups are avoided. Hayashi at page 868, col. 1 (4). Hayashi discusses criteria for effective one-pot synthesis of, including the case where the intermediate compound is unstable or hazardous. Hayashi at page 868, col. 2 (6.1).
Obviousness Rationale
One of ordinary skill is motivated to obtain the following compound (falling with the scope of claim 1):
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in view of the catalytic utility taught by Crowther. One of ordinary skill is further motivated to synthesize this compound by adapting Butakoff’s procedure by replacing Butakoff’s LiCp= with Li[C5H5] (claimed Formula 2-1) in the first step and employing claimed compound 3-1 in the second step so as to arrive at the following synthetic method producing desired claimed compound 1-1 (where the ZnCl4 represents the claim 1 compound of formula 4).
Proposed Modified Procedure of Butakof
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As shown above, one of ordinary skill is motivated to employ the solution of the intermediate directly in the next step (without the isolation step taught by Butakoff) in view of Anderson’s and Hayashi’s teachings that a one-pot synthesis of a target molecule in the same reaction vessel is widely considered to be an efficient approach in synthetic organic chemistry. One of ordinary skill therefore arrives at each and every limitation of claim 1, Formula 1-1.
One of ordinary skill has a reasonable expectation of success because the reactant compounds 2-1 and 3-1 proposed to be respectively substituted for Butakof’s LiCp= and are structurally similar to the extent that the cyclopentadiene ring is substituted only with hydrogen or alkyl groups, which all appear to do well in Butakof’s synthesis. Claim 1 is therefore obvious.
The limitations of claim 6 are met because the solvent in the proposed process is ether or tetrahydrofuran (THF).
The limitations of claims 8 and 9 are met because Butakoff employs temperatures within these ranges, which would therefore be an obvious starting point for one of ordinary skill to optimize temperature. Further, generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. MPEP § 2144.04(II)(A) (citing In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) ("[w]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation”)).
The further concentrations limitations of claim 11 are not a patentable distinction pursuant to § 103. Butakoff employs concentrations of Formula 2 and Formula 3 within these ranges, which would therefore be an obvious starting point for one of ordinary skill to optimize concentration. Further as noted above, generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. MPEP § 2144.04(II)(A).
Claim 12 is obvious because Butakoff teaches that the metallocene product 4 is isolated using an extractive workup that involves filtering. Butakoff at page 497, col. 2
Applicant’s Argument
Applicant argues that Butakoff teaches reaction of instantly claimed Formula 2-1 as the second addition step, whereas claim 1 requires Formula 2-1 as the first step. Applicant argues that therefore the order of the preparation method in claim 1 differs from the order of the preparation method pointed out by the examiner.
This argument is not persuasive using compound 2-1 in the first step and 3-1 in the second step or vice versa simply represents a suitable alternative order of reagent addition. MPEP § 2144.04 (IV)(C).1 One of ordinary skill has a reasonable expectation that compounds 2-1 and 3-1 are alternatively employable in Butakoff’s first and second steps because in each case the cyclopentadiene ring is substituted only with hydrogen or alkyl groups, which all appear to do well in Butakof’s synthesis. MPEP § 2144.09.
Conclusion
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ALEXANDER R. PAGANO
Examiner
Art Unit 1692
/ALEXANDER R PAGANO/Primary Examiner, Art Unit 1692
1 MPEP § 2144.04 (IV)(C) (citing Ex parte Rubin, 128 USPQ 440 (Bd. App. 1959) (Prior art reference disclosing a process of making a laminated sheet wherein a base sheet is first coated with a metallic film and thereafter impregnated with a thermosetting material was held to render prima facie obvious claims directed to a process of making a laminated sheet by reversing the order of the prior art process steps.). See also In re Burhans, 154 F.2d 690, 69 USPQ 330 (CCPA 1946) (selection of any order of performing process steps is prima facie obvious in the absence of new or unexpected results); In re Gibson, 39 F.2d 975, 5 USPQ 230 (CCPA 1930) (Selection of any order of mixing ingredients is prima facie obvious.).