- Development of a Scalable Process for the Insecticidal Candidate Tyclopyrazoflor. Part 3. A Scalable Synthesis of Methyl 3-((3,3,3-Trifluoropropyl)thio)propanoate via Thiol-Ene Chemistry
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Optimization of the thiol-ene reaction for the preparation of methyl 3-((3,3,3-trifluoropropyl)thio)propanoate (4), a key intermediate in the synthesis of the sap-feeding insecticidal candidate tyclopyrazoflor (1), is described. The major challenge with the radical thiol-ene chemistry was control of the regioselectivity between the linear and branched products. Reducing the radical initiation temperature was found to be the key variable in controlling the selectivity. Because of the high cost and storage challenges associated with the use of the room-temperature diazo initiator 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) (V-70), a two-component initiator system consisting of benzoyl peroxide and N,N-dimethylaniline was developed, allowing for radical initiation at temperatures as low as -15 °C. Application of semibatch operation gave 90:1 selectivity favoring the linear product. The overall yield and selectivity of the radical thiol-ene reaction were improved from 78% yield and 11:1 selectivity with azobis(isobutyronitrile) in batch mode to 91% yield and 90:1 selectivity with the two-component system in semibatch mode, further eliminating the need for a fractional distillation purification step.
- Gray, Kaitlyn C.,Heider, Patrick,McGough, Patrick,Ondari, Mark,Devaraj, Jayachandran,Yang, Qiang,Frycek, George,Graham, Brian,Neuman, Joseph,Lorsbach, Beth A.,Zhang, Yu
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p. 2142 - 2147
(2019/11/02)
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- PROCESSES FOR THE PREPARATION OF PESTICIDAL COMPOUNDS
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The disclosure relates to efficient and economical synthetic chemical processes for the preparation of pesticidal thioethers. Further, the disclosure relates to certain novel compounds useful in the preparation of pesticidal thioethers.
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Paragraph 0067; 0068
(2018/07/29)
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- PESTICIDAL COMPOSITIONS AND PROCESSES RELATED THERETO
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This document discloses molecules having the following formula (“Formula One”): and processes related thereto.
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Paragraph 0626; 0627
(2016/05/02)
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- LOW TEMPERATURE FREE RADICAL INITIATED PROCESS FOR THE PREPARATION OF 3-((3,3,3-TRIFLUOROPROPYL)THIO)PROPIONIC ACID AND ESTERS THEREOF
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3-((3,3,3-Trifluoropropyl)thio)propionic acid and esters thereof are prepared by a low temperature free radical process involving the free radical coupling of 3-mercaptopropionic acid and esters thereof with 3,3,3-trifluoropropene. The ratio of linear to branched isomer is enhanced.
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Page/Page column 4
(2016/04/01)
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- PHOTOCHEMICAL PROCESS FOR THE PREPARATION OF 3-((3,3,3-TRIFLUOROPROPYL)THIO)PROPIONIC ACID AND ESTERS THEREOF
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3-((3,3,3-Trifluoropropyl)thio)propionic acid and esters thereof are prepared by a photochemical process involving the free radical coupling of 3-mercaptopropionic acid and esters thereof with 3,3,3-trifluoropropene. The ratio of linear to branched isomer is enhanced.
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Paragraph 0022-0023
(2015/12/07)
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- PROCESSES FOR THE PREPARATION OF PESTICIDAL COMPOUNDS
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The present application provides processes for making pesticidal compounds and compounds useful both as pesticides and in the making of pesticidal compounds.
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Paragraph 0033-0034
(2015/04/28)
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- PROCESSES FOR THE PREPARATION OF PESTICIDAL COMPOUNDS
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The present application provides processes for making pesticidal compounds and compounds useful both as pesticides and in the making of pesticidal compounds.
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Paragraph 0025
(2015/04/28)
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- PROCESSES FOR THE PREPARATION OF PESTICIDAL COMPOUNDS
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The present application provides processes for making pesticidal compounds and compounds useful both as pesticides and in the making of pesticidal compounds.
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Paragraph 0061; 0063
(2015/04/28)
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- PROCESSES FOR THE PREPARATION OF PESTICIDAL COMPOUNDS
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The present application provides processes for making pesticidal compounds and compounds useful both as pesticides and in the making of pesticidal compounds.
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Paragraph 0061; 0063
(2015/04/28)
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- PROCESSES FOR THE PREPARATION OF PESTICIDAL COMPOUNDS
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The present application provides processes for making pesticidal compounds and compounds useful both as pesticides and in the making of pesticidal compounds.
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Paragraph 0047; 0048
(2015/04/28)
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- PESTICIDAL COMPOSITIONS AND PROCESSES RELATED THERETO
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This document discloses molecules having the following formula (“Formula One”): and processes related thereto.
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Paragraph 0454; 0455
(2013/05/09)
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- PESTICIDAL COMPOSITIONS AND PROCESSES RELATED THERETO
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This document discloses molecules having the following formula (“Formula One”): and processes related thereto.
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Paragraph 0626-0627
(2013/11/06)
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- Fluoride ion-catalyzed conjugate addition for easy synthesis of 3-sulfanylpropionic acid from thiol and α,β-unsaturated carboxylic acid
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3-Sulfanylpropionic acids are obtained in excellent yields by proceeding through a simple, mild, and efficient procedure utilizing tetrabutylammonium fluoride (TBAF) as catalyst.
- Gao, Shijay,Tseng, Chi,Tsai, Cheng Hsuan,Yao, Ching-Fa
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p. 1955 - 1961
(2008/09/17)
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- Preparation, reactions and physical properties of segmented 2-(perfluoroalkyl)ethanesulfinic acids and their derivatives. the role of the perfluoroalkyl group in finding new and useful compounds and in searching out new chemistry
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2-(Perfluoroalkyl)ethanesulfinic acids of the formula RFCH2CH2SO2H (2, where RF=n-C6F13, or n-C8F17) are synthesized from the thiol, RFCH2CH2SH (1). These segmented acids 2 have sharp melting point (mp) and can be recrystallized. The C6 or C8 perfluoroalkyl group confers unusual "fluophilic" properties to acids 2 and their derivatives. Water solutions of acids 2 and their Na, K, Cs and Bu4N salts are highly surface active and stable for several days, and are more effective in reducing surface tension at the air/water interface than sodium n-perfluorooctanesulfonate (10). Sodium salts 2 (C6, C8) are converted to K and Cs salts by methathesis in high yield. However, the amphiphilic Bu4N salts of 2 (C6, C8) are best prepared in a biphasic system (C6, 99.6% yield). Acids 2 are synthesized by three methods. (1) Oxidation of the C8 thiol 1 (at -35°C) by m-CPBA gives acid 2 (C8) in 73% yield and unwanted disulfide (3) in 27% yield. The bulky, strongly electronegative RF group of 1 may slow oxidation of the RSOH (intermediate) to allow disproportionation with RSH into disulfide 3 and water. (2) Hydrolysis of RFCH2CH2SO2SCH2CH 2RF (4) with strong base gives salt 2 (C6, or C8; 92% yield). (3) Heating sulfone, RFCH2CH2SO2CH2CH 2Y (8) with a base (M2CO3) eliminates RFCH2CH2SO2M (2, M=Na, K, Cs) in 95-100% yield (C6, C8). Alternatively, 8 with the sodium thiolate of 1 gives RFCnH2nSCH2CH2Y (7, 90%) and sodium salt 2 (C6, 95%). Conjugate addition of the RFCH2CH2SO2- to CH2CHY gives sulfones 8, and RFCH2CH2SO2- adds stereospecifically to cyclohexene oxide, giving the trans-adduct 13. RFCH2CH2SO2H (2), with azo initiator, telomerizes acrylamide to a water-soluble, surface active product.
- Brace, Neal O.
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