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Stefan Abele - One of the best experts on this subject based on the ideXlab platform.

  • practical synthesis of a s1p receptor 1 agonist via a guareschi Thorpe Reaction
    Organic Process Research & Development, 2016
    Co-Authors: Gunther Schmidt, Cyrille Lescop, Martin Bolli, Stefan Abele
    Abstract:

    A practical synthesis of S1P receptor 1 agonist ACT-334441 (1) through late-stage convergent coupling of two key intermediates is described. The first intermediate is 2-cyclopentyl-6-methoxyisonicotinic acid whose skeleton was built from 1-cyclopentylethanone, ethyl oxalate, and cyanoacetate in a Guareschi–Thorpe Reaction in 42% yield over five steps. The second, chiral intermediate, is a phenol ether derived from enantiomerically pure (R)-isopropylidene glycerol ((R)-solketal) and 3-ethyl-4-hydroxy-5-methylbenzonitrile in 71% yield in a one-pot Reaction. The overall sequence entails 18 chemical steps with 10 isolated intermediates. All raw materials are cheap and readily available in bulk quantities, the Reaction conditions match with standard pilot plant equipment, and the route reproducibly afforded 3–20 kg of 1 in excellent purity and yield for clinical studies.

  • Practical Synthesis of a S1P Receptor 1 Agonist via a Guareschi–Thorpe Reaction
    Organic Process Research & Development, 2016
    Co-Authors: Gunther Schmidt, Cyrille Lescop, Martin Bolli, Stefan Abele
    Abstract:

    A practical synthesis of S1P receptor 1 agonist ACT-334441 (1) through late-stage convergent coupling of two key intermediates is described. The first intermediate is 2-cyclopentyl-6-methoxyisonicotinic acid whose skeleton was built from 1-cyclopentylethanone, ethyl oxalate, and cyanoacetate in a Guareschi–Thorpe Reaction in 42% yield over five steps. The second, chiral intermediate, is a phenol ether derived from enantiomerically pure (R)-isopropylidene glycerol ((R)-solketal) and 3-ethyl-4-hydroxy-5-methylbenzonitrile in 71% yield in a one-pot Reaction. The overall sequence entails 18 chemical steps with 10 isolated intermediates. All raw materials are cheap and readily available in bulk quantities, the Reaction conditions match with standard pilot plant equipment, and the route reproducibly afforded 3–20 kg of 1 in excellent purity and yield for clinical studies.

  • Practical Synthesis of a S1P Receptor 1 Agonist via a Guareschi–Thorpe Reaction
    2016
    Co-Authors: Gunther Schmidt, Martin H. Bolli, Cyrille Lescop, Stefan Abele
    Abstract:

    A practical synthesis of S1P receptor 1 agonist ACT-334441 (1) through late-stage convergent coupling of two key intermediates is described. The first intermediate is 2-cyclopentyl-6-methoxyisonicotinic acid whose skeleton was built from 1-cyclopentylethanone, ethyl oxalate, and cyanoacetate in a Guareschi–Thorpe Reaction in 42% yield over five steps. The second, chiral intermediate, is a phenol ether derived from enantiomerically pure (R)-isopropylidene glycerol ((R)-solketal) and 3-ethyl-4-hydroxy-5-methylbenzonitrile in 71% yield in a one-pot Reaction. The overall sequence entails 18 chemical steps with 10 isolated intermediates. All raw materials are cheap and readily available in bulk quantities, the Reaction conditions match with standard pilot plant equipment, and the route reproducibly afforded 3–20 kg of 1 in excellent purity and yield for clinical studies

  • Practical and Scalable Synthesis of S1P1 Receptor Agonist ACT-209905
    Organic Process Research & Development, 2012
    Co-Authors: Gunther Schmidt, Martin Bolli, Stefan Reber, Stefan Abele
    Abstract:

    A practical and scalable route for the fast delivery of 12 kg of S1P1 agonist (ACT-209905) has been developed. ACT-209905 is composed of an amino pyridine group, an oxadiazole spacer, a 2-ethyl-5-methylphenol moiety and a chiral 1-amino-2-propanol side chain. The convergent synthesis consists of 16 steps with 9 isolated intermediates and is chromatography-free. Key building blocks are accessed from low-cost starting materials, such as acetone, diethyl oxalate, cyanoacetamide, and 2-ethyl-5-methyl aniline. A Negishi coupling that was troubled by the use of metal reagents and concomitant metal waste streams has been replaced by a less expensive Guareschi–Thorpe Reaction to build up an amino isonicotinic acid. The chiral 1-amino-2-propanol moiety was secured by selective ring-opening of an epoxide with lithium hexamethyldisilazide as an ammonia surrogate, thus omitting the notorious double alkylated byproduct.

  • Practical and Scalable Synthesis of S1P1 Receptor Agonist ACT-209905
    2012
    Co-Authors: Gunther Schmidt, Martin H. Bolli, Stefan Reber, Stefan Abele
    Abstract:

    A practical and scalable route for the fast delivery of 12 kg of S1P1 agonist (ACT-209905) has been developed. ACT-209905 is composed of an amino pyridine group, an oxadiazole spacer, a 2-ethyl-5-methylphenol moiety and a chiral 1-amino-2-propanol side chain. The convergent synthesis consists of 16 steps with 9 isolated intermediates and is chromatography-free. Key building blocks are accessed from low-cost starting materials, such as acetone, diethyl oxalate, cyanoacetamide, and 2-ethyl-5-methyl aniline. A Negishi coupling that was troubled by the use of metal reagents and concomitant metal waste streams has been replaced by a less expensive Guareschi–Thorpe Reaction to build up an amino isonicotinic acid. The chiral 1-amino-2-propanol moiety was secured by selective ring-opening of an epoxide with lithium hexamethyldisilazide as an ammonia surrogate, thus omitting the notorious double alkylated byproduct

Gunther Schmidt - One of the best experts on this subject based on the ideXlab platform.

  • practical synthesis of a s1p receptor 1 agonist via a guareschi Thorpe Reaction
    Organic Process Research & Development, 2016
    Co-Authors: Gunther Schmidt, Cyrille Lescop, Martin Bolli, Stefan Abele
    Abstract:

    A practical synthesis of S1P receptor 1 agonist ACT-334441 (1) through late-stage convergent coupling of two key intermediates is described. The first intermediate is 2-cyclopentyl-6-methoxyisonicotinic acid whose skeleton was built from 1-cyclopentylethanone, ethyl oxalate, and cyanoacetate in a Guareschi–Thorpe Reaction in 42% yield over five steps. The second, chiral intermediate, is a phenol ether derived from enantiomerically pure (R)-isopropylidene glycerol ((R)-solketal) and 3-ethyl-4-hydroxy-5-methylbenzonitrile in 71% yield in a one-pot Reaction. The overall sequence entails 18 chemical steps with 10 isolated intermediates. All raw materials are cheap and readily available in bulk quantities, the Reaction conditions match with standard pilot plant equipment, and the route reproducibly afforded 3–20 kg of 1 in excellent purity and yield for clinical studies.

  • Practical Synthesis of a S1P Receptor 1 Agonist via a Guareschi–Thorpe Reaction
    Organic Process Research & Development, 2016
    Co-Authors: Gunther Schmidt, Cyrille Lescop, Martin Bolli, Stefan Abele
    Abstract:

    A practical synthesis of S1P receptor 1 agonist ACT-334441 (1) through late-stage convergent coupling of two key intermediates is described. The first intermediate is 2-cyclopentyl-6-methoxyisonicotinic acid whose skeleton was built from 1-cyclopentylethanone, ethyl oxalate, and cyanoacetate in a Guareschi–Thorpe Reaction in 42% yield over five steps. The second, chiral intermediate, is a phenol ether derived from enantiomerically pure (R)-isopropylidene glycerol ((R)-solketal) and 3-ethyl-4-hydroxy-5-methylbenzonitrile in 71% yield in a one-pot Reaction. The overall sequence entails 18 chemical steps with 10 isolated intermediates. All raw materials are cheap and readily available in bulk quantities, the Reaction conditions match with standard pilot plant equipment, and the route reproducibly afforded 3–20 kg of 1 in excellent purity and yield for clinical studies.

  • Practical Synthesis of a S1P Receptor 1 Agonist via a Guareschi–Thorpe Reaction
    2016
    Co-Authors: Gunther Schmidt, Martin H. Bolli, Cyrille Lescop, Stefan Abele
    Abstract:

    A practical synthesis of S1P receptor 1 agonist ACT-334441 (1) through late-stage convergent coupling of two key intermediates is described. The first intermediate is 2-cyclopentyl-6-methoxyisonicotinic acid whose skeleton was built from 1-cyclopentylethanone, ethyl oxalate, and cyanoacetate in a Guareschi–Thorpe Reaction in 42% yield over five steps. The second, chiral intermediate, is a phenol ether derived from enantiomerically pure (R)-isopropylidene glycerol ((R)-solketal) and 3-ethyl-4-hydroxy-5-methylbenzonitrile in 71% yield in a one-pot Reaction. The overall sequence entails 18 chemical steps with 10 isolated intermediates. All raw materials are cheap and readily available in bulk quantities, the Reaction conditions match with standard pilot plant equipment, and the route reproducibly afforded 3–20 kg of 1 in excellent purity and yield for clinical studies

  • Practical and Scalable Synthesis of S1P1 Receptor Agonist ACT-209905
    Organic Process Research & Development, 2012
    Co-Authors: Gunther Schmidt, Martin Bolli, Stefan Reber, Stefan Abele
    Abstract:

    A practical and scalable route for the fast delivery of 12 kg of S1P1 agonist (ACT-209905) has been developed. ACT-209905 is composed of an amino pyridine group, an oxadiazole spacer, a 2-ethyl-5-methylphenol moiety and a chiral 1-amino-2-propanol side chain. The convergent synthesis consists of 16 steps with 9 isolated intermediates and is chromatography-free. Key building blocks are accessed from low-cost starting materials, such as acetone, diethyl oxalate, cyanoacetamide, and 2-ethyl-5-methyl aniline. A Negishi coupling that was troubled by the use of metal reagents and concomitant metal waste streams has been replaced by a less expensive Guareschi–Thorpe Reaction to build up an amino isonicotinic acid. The chiral 1-amino-2-propanol moiety was secured by selective ring-opening of an epoxide with lithium hexamethyldisilazide as an ammonia surrogate, thus omitting the notorious double alkylated byproduct.

  • Practical and Scalable Synthesis of S1P1 Receptor Agonist ACT-209905
    2012
    Co-Authors: Gunther Schmidt, Martin H. Bolli, Stefan Reber, Stefan Abele
    Abstract:

    A practical and scalable route for the fast delivery of 12 kg of S1P1 agonist (ACT-209905) has been developed. ACT-209905 is composed of an amino pyridine group, an oxadiazole spacer, a 2-ethyl-5-methylphenol moiety and a chiral 1-amino-2-propanol side chain. The convergent synthesis consists of 16 steps with 9 isolated intermediates and is chromatography-free. Key building blocks are accessed from low-cost starting materials, such as acetone, diethyl oxalate, cyanoacetamide, and 2-ethyl-5-methyl aniline. A Negishi coupling that was troubled by the use of metal reagents and concomitant metal waste streams has been replaced by a less expensive Guareschi–Thorpe Reaction to build up an amino isonicotinic acid. The chiral 1-amino-2-propanol moiety was secured by selective ring-opening of an epoxide with lithium hexamethyldisilazide as an ammonia surrogate, thus omitting the notorious double alkylated byproduct

Martin Bolli - One of the best experts on this subject based on the ideXlab platform.

  • Practical Synthesis of a S1P Receptor 1 Agonist via a Guareschi–Thorpe Reaction
    Organic Process Research & Development, 2016
    Co-Authors: Gunther Schmidt, Cyrille Lescop, Martin Bolli, Stefan Abele
    Abstract:

    A practical synthesis of S1P receptor 1 agonist ACT-334441 (1) through late-stage convergent coupling of two key intermediates is described. The first intermediate is 2-cyclopentyl-6-methoxyisonicotinic acid whose skeleton was built from 1-cyclopentylethanone, ethyl oxalate, and cyanoacetate in a Guareschi–Thorpe Reaction in 42% yield over five steps. The second, chiral intermediate, is a phenol ether derived from enantiomerically pure (R)-isopropylidene glycerol ((R)-solketal) and 3-ethyl-4-hydroxy-5-methylbenzonitrile in 71% yield in a one-pot Reaction. The overall sequence entails 18 chemical steps with 10 isolated intermediates. All raw materials are cheap and readily available in bulk quantities, the Reaction conditions match with standard pilot plant equipment, and the route reproducibly afforded 3–20 kg of 1 in excellent purity and yield for clinical studies.

  • practical synthesis of a s1p receptor 1 agonist via a guareschi Thorpe Reaction
    Organic Process Research & Development, 2016
    Co-Authors: Gunther Schmidt, Cyrille Lescop, Martin Bolli, Stefan Abele
    Abstract:

    A practical synthesis of S1P receptor 1 agonist ACT-334441 (1) through late-stage convergent coupling of two key intermediates is described. The first intermediate is 2-cyclopentyl-6-methoxyisonicotinic acid whose skeleton was built from 1-cyclopentylethanone, ethyl oxalate, and cyanoacetate in a Guareschi–Thorpe Reaction in 42% yield over five steps. The second, chiral intermediate, is a phenol ether derived from enantiomerically pure (R)-isopropylidene glycerol ((R)-solketal) and 3-ethyl-4-hydroxy-5-methylbenzonitrile in 71% yield in a one-pot Reaction. The overall sequence entails 18 chemical steps with 10 isolated intermediates. All raw materials are cheap and readily available in bulk quantities, the Reaction conditions match with standard pilot plant equipment, and the route reproducibly afforded 3–20 kg of 1 in excellent purity and yield for clinical studies.

  • Practical and Scalable Synthesis of S1P1 Receptor Agonist ACT-209905
    Organic Process Research & Development, 2012
    Co-Authors: Gunther Schmidt, Martin Bolli, Stefan Reber, Stefan Abele
    Abstract:

    A practical and scalable route for the fast delivery of 12 kg of S1P1 agonist (ACT-209905) has been developed. ACT-209905 is composed of an amino pyridine group, an oxadiazole spacer, a 2-ethyl-5-methylphenol moiety and a chiral 1-amino-2-propanol side chain. The convergent synthesis consists of 16 steps with 9 isolated intermediates and is chromatography-free. Key building blocks are accessed from low-cost starting materials, such as acetone, diethyl oxalate, cyanoacetamide, and 2-ethyl-5-methyl aniline. A Negishi coupling that was troubled by the use of metal reagents and concomitant metal waste streams has been replaced by a less expensive Guareschi–Thorpe Reaction to build up an amino isonicotinic acid. The chiral 1-amino-2-propanol moiety was secured by selective ring-opening of an epoxide with lithium hexamethyldisilazide as an ammonia surrogate, thus omitting the notorious double alkylated byproduct.

Xue-long Hou - One of the best experts on this subject based on the ideXlab platform.

Lajos Kovács - One of the best experts on this subject based on the ideXlab platform.

  • Unexpected Thorpe Reaction of an α-Alkoxynitrile
    2013
    Co-Authors: Lajos Kovács
    Abstract:

    gave the dimer 5 instead of the expected C1-elongated product 3. The formation of compound 5 is explained in terms of anion formation and self-condensation, a variant of the Thorpe Reaction. Scrutinizing the 1 H NMR spectra revealed that the enamine tautomer 5b is predominant over the imine 5a in the solvents investigated

  • Unexpected Thorpe Reaction of an α-Alkoxynitrile
    Molecules, 2000
    Co-Authors: Lajos Kovács
    Abstract:

    α-Alkoxynitrile 1 in the presence of tris(methylthio)methyllithium 2 at –78ºC gave the dimer 5 instead of the expected C1-elongated product 3. The formation of compound 5 is explained in terms of anion formation and self-condensation, a variant of the Thorpe Reaction. Scrutinizing the 1H NMR spectra revealed that the enamine tautomer 5b is predominant over the imine 5a in the solvents investigated

  • Unexpected Thorpe Reaction of an α-Alkoxynitrile
    Molecules, 2000
    Co-Authors: Lajos Kovács
    Abstract:

    Lajos KovacsDepartment of Medicinal Chemistry, University of Szeged, Dom ter 8., H-6720 Szeged, HungaryTel.: +36 62 54 51 45, Fax: +36 62 42 52 62, E-mail: kovacs@ovrisc.mdche.u-szeged.hu,URL: http://www.mdche.u-szeged.hu/staff/kovacs.htmReceived: 19 January 2000 / Accepted: 14 February 2000 / Published: 17 February 2000Abstract: α-Alkoxynitrile 1 in the presence of tris(methylthio)methyllithium 2 at –78oCgave the dimer 5 instead of the expected C