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17552115Acid-catalyzed Pictet-Spengler reaction with binaphthalenedisulfonic acid (MW56-1 to MW56-4)
Experiments
profiles.google.com-micha.wolfleMichael Wolfle starting material (see MW56-3) [data=text]897[/data] - heated for a furter 24 h (reaction time 30 h) LCMS (column: C18 waters sunfire, gradient A: water, B acetonitrile + 0.1% formic acid; 0 to 100% B over 15 min, flow 0.2 mL/min) [data=text]911[/data] -> starting material, small amount of PZQ [b]MW56-2:[/b] A solution of [url=http://www.ourexperiment.org/racemic_pzq/1555][b]MW51-1[/b][/url] (18.5 mg, 50.0 µmol, M.W. 370.4 g/mol) and [url=http://www.ourexperiment.org/racemic_pzq/587]1,1’-Binaphthalene-2,2’-disulfonic acid[/url] (2.1 mg, 5.0 µmol, 10 mol%, M.W. 414.5 g/mol) in toluene (1 mL) was stirred for 16 h at 70°C. Product, see: [url=http://www.ourexperiment.org/racemic_pzq/1654][b]MW53-4[/b][/url] LCMS (ESI +): m/z = 339 [hemiacetal] (100), 393 [M+Na] (30), 763 [2M+Na] (30). [data=text]899[/data] - heated for a furter 24 h LCMS: starting material, small amount of product [data=text]913[/data] [b]MW56-3:[/b] A solution of [url=http://www.ourexperiment.org/racemic_pzq/386][b]MW40-1[/b][/url] (21.8 mg, 50.0 µmol, M.W. 436.5 g/mol) and [url=http://www.ourexperiment.org/racemic_pzq/587]1,1’-Binaphthalene-2,2’-disulfonic acid[/url] (2.1 mg, 5.0 µmol, 10 mol%, M.W. 414.5 g/mol) in toluene (1 mL) was stirred for 16 h at 70°C. LCMS (ESI +): m/z = 405 [hemiacetal] (100), 459 [M+Na] (30). [data=text]901[/data] - heated for a furter 24 h [data=text]915[/data][data=text]917[/data] [b]MW56-4:[/b] A solution of [url=http://www.ourexperiment.org/racemic_pzq/1597][b]MW52-1[/b][/url] (21.5 mg, 50.0 µmol, M.W. 430.5 g/mol) and [url=http://www.ourexperiment.org/racemic_pzq/587]1,1’-Binaphthalene-2,2’-disulfonic acid[/url] (2.1 mg, 5.0 µmol, 10 mol%, M.W. 414.5 g/mol) in toluene (1 mL) was stirred for 16 h at 70°C. Product, see: [url=http://www.ourexperiment.org/racemic_pzq//1658][b]MW54-3[/b][/url] LCMS (ESI +): m/z = 399 [hemiacetal] (100), 453 [M+Na] (30). [data=text]903[/data] - heated for a furter 24 h [data=text]919[/data] - Catalyst is sparingly soluble in toluene at rt -> temperature raised to 70°C after 30 min. After 16 h: - TLC (ethyl acetate, 100%; stain:ceric ammonium molybdate) showed no difference between starting material and product (no reaction?) [data]895[/data] - 10 µL of each sample were withdrawn, purified by a small column (silica gel, ethyl acetate, 100%), evaporated and dissolved in acetonitrile (c= 0.05 mg/mL), filtered by a syringe filter and evaluated by LC/MS. LCMS showed mass of the hemiaminals but also the starting material [M+Na] and the dimere of it and only one LC peak in the PDA spectrum -> hemiaminal or fragmentation of the starting material ?? [data]907[/data] After 30 h: [data]905[/data] LCMS of reaction and starting material (fragmentation?) See also: [url=http://www.ourexperiment.org/racemic_pzq/1765]Acid-catalyzed Pictet-Spengler reaction with methanesulfonic acid (MW56-5 to MW56-8)[/url] [b]Results:[/b] -> non-selective reaction for MW56-5 and MW56-6 (unactivated compound) - increasing the catalyst concentration -> almost selective Pictet-Spengler reaction of both dimethoxy-substituted Ugi-intermediates]]>rac-1,1’-Binaphthalene-2,2’-disulfonic acid as a strong Bronsted-acidic catalyst.

Reaction Scheme


See also:
  • Attempts to the acid-mediated Pictet-Spengler cyclization of the ‘Ugi intermediate’ MW29 (MW31)
  • Cleavage of the dimethoxy acetal of 2-((2,2-dimethoxyethyl)amino)-N-phenethylacetamide hydrochloride MW7 (MW42-1 to MW42-7)
  • Attempts to the Bronstedt-acid catalysed Pictet-Spengler cyclization using N,N’-bis
  • [3,5-bis(trifluoromethyl)phenyl]thiourea (MW44)
  • Attempts to the Bronstedt-acid catalysed Pictet-Spengler cyclization using BINOL-N-triflyl phosphoramide (MW41)
    and following experiments:
  • Acid-catalyzed Pictet-Spengler reaction with methanesulfonic acid (MW56-5 to MW56-8)
  • Continuation: Acid-catalyzed Pictet-Spengler reaction with methanesulfonic acid (MW56-9 to MW56-12)

    Hazard and Risk Assessment:
  • HRAF MW56.pdf


    Start time: 6:30 pm 14/03/2011
    End time: 9:30 am 16/03/2011

    MW56-1:
    A solution of MW29-4 (18.8 mg, 50.0 µmol, M.W. 376.5 g/mol) and 1,1’-Binaphthalene-2,2’-disulfonic acid (2.1 mg, 5.0 µmol, 10 mol%, M.W. 414.5 g/mol) in toluene (1 mL) was stirred for 16 h at 70°C.
    Product, see: PZQ

    LCMS (ESI +): m/z (%) = 345 [hemiacetal] (100), 399 [M+Na] (30), 775 [2M+Na] (30). -> starting material (see MW56-3)
    Data: LCMS MW56-1 after 16h.pdf

    - heated for a furter 24 h (reaction time 30 h)
    LCMS (column: C18 waters sunfire, gradient A: water, B acetonitrile + 0.1% formic acid; 0 to 100% B over 15 min, flow 0.2 mL/min)
    Data: LCMS MW56-1 (30h).pdf -> starting material, small amount of PZQ

    MW56-2:
    A solution of MW51-1 (18.5 mg, 50.0 µmol, M.W. 370.4 g/mol) and 1,1’-Binaphthalene-2,2’-disulfonic acid (2.1 mg, 5.0 µmol, 10 mol%, M.W. 414.5 g/mol) in toluene (1 mL) was stirred for 16 h at 70°C.
    Product, see: MW53-4
    LCMS (ESI +): m/z = 339 [hemiacetal] (100), 393 [M+Na] (30), 763 [2M+Na] (30). Data: LCMS MW56-2 after 16h.pdf
    - heated for a furter 24 h
    LCMS: starting material, small amount of product
    Data: LCMS MW56-2 (30h).pdf

    MW56-3:
    A solution of MW40-1 (21.8 mg, 50.0 µmol, M.W. 436.5 g/mol) and 1,1’-Binaphthalene-2,2’-disulfonic acid (2.1 mg, 5.0 µmol, 10 mol%, M.W. 414.5 g/mol) in toluene (1 mL) was stirred for 16 h at 70°C.
    LCMS (ESI +): m/z = 405 [hemiacetal] (100), 459 [M+Na] (30). Data: LCMS MW56-3 after 16h.pdf
    - heated for a furter 24 h
    Data: LCMS MW56-3 (30h).pdfData: LCMS MW40-1 starting material for MW56-3.pdf

    MW56-4:
    A solution of MW52-1 (21.5 mg, 50.0 µmol, M.W. 430.5 g/mol) and 1,1’-Binaphthalene-2,2’-disulfonic acid (2.1 mg, 5.0 µmol, 10 mol%, M.W. 414.5 g/mol) in toluene (1 mL) was stirred for 16 h at 70°C.
    Product, see: MW54-3
    LCMS (ESI +): m/z = 399 [hemiacetal] (100), 453 [M+Na] (30). Data: LCMS MW56-4 after 16h.pdf
    - heated for a furter 24 h
    Data: LCMS MW56-4 (30h).pdf

    - Catalyst is sparingly soluble in toluene at rt -> temperature raised to 70°C after 30 min.

    After 16 h:
    - TLC (ethyl acetate, 100%; stain:ceric ammonium molybdate) showed no difference between starting material and product (no reaction?)
    TLC MW56-1 to MW56-4.JPG

    - 10 µL of each sample were withdrawn, purified by a small column (silica gel, ethyl acetate, 100%), evaporated and dissolved in acetonitrile (c= 0.05 mg/mL), filtered by a syringe filter and evaluated by LC/MS.
    LCMS showed mass of the hemiaminals but also the starting material [M+Na] and the dimere of it and only one LC peak in the PDA spectrum
    -> hemiaminal or fragmentation of the starting material ??
    hemiaminal.png


    After 30 h:
    TLC MW56-1 to MW56-8.JPG


    LCMS of reaction and starting material (fragmentation?)

    See also: Acid-catalyzed Pictet-Spengler reaction with methanesulfonic acid (MW56-5 to MW56-8)

    Results:
    -> non-selective reaction for MW56-5 and MW56-6 (unactivated compound) - increasing the catalyst concentration
    -> almost selective Pictet-Spengler reaction of both dimethoxy-substituted Ugi-intermediates
    Linked Posts
    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id_MW561_to_MW564.xml?revision=1787https://www.ourexperiment.org/racemic_pzq/1755/Acidcatalyzed_PictetSpengler_reaction_with_binaphthalenedisulfonic_acid_MW561_to_MW564.xml?revision=1788https://www.ourexperiment.org/racemic_pzq/1755/Acidcatalyzed_PictetSpengler_reaction_with_binaphthalenedisulfonic_acid_MW561_to_MW564.xml?revision=1789https://www.ourexperiment.org/racemic_pzq/1755/Acidcatalyzed_PictetSpengler_reaction_with_binaphthalenedisulfonic_acid_MW561_to_MW564.xml?revision=1790https://www.ourexperiment.org/racemic_pzq/1755/Acidcatalyzed_PictetSpengler_reaction_with_binaphthalenedisulfonic_acid_MW561_to_MW564.xml?revision=1791https://www.ourexperiment.org/racemic_pzq/1755/Acidcatalyzed_PictetSpengler_reaction_with_binaphthalenedisulfonic_acid_MW561_to_MW564.xml?revision=1797https://www.ourexperiment.org/racemic_pzq/1755/Acidcatalyzed_PictetSpengler_reaction_with_binaphthalenedisulfonic_acid_MW561_to_MW564.xml?revision=1867https://www.ourexperiment.org/racemic_pzq/1755/Acidcatalyzed_PictetSpengler_reaction_with_binaphthalenedisulfonic_acid_MW561_to_MW564.xml?revision=2115https://www.ourexperiment.org/racemic_pzq/1755/Acidcatalyzed_PictetSpengler_reaction_with_binaphthalenedisulfonic_acid_MW561_to_MW564.xml?revision=693832Re: Acid-catalyzed Pictet-Spengler reaction with binaphthalenedisulfonic acid (MW56-1 to MW56-4)ErrorRe: Acid-catalyzed Pictet-Spengler reaction with binaphthalenedisulfonic acid (MW56-1 to MW56-4)That's odd. No reaction at all? I'd expect the acetal to go, even if the cyclization does not. Your follow-up reaction with MeSO3H is the right thing to do, yes.That's odd. No reaction at all? I'd expect the acetal to go, even if the cyclization does not. Your follow-up reaction with MeSO3H is the right thing to do, yes.2011-03-15T10:14:35+00:00
    17556938Acid-catalyzed Pictet-Spengler reaction with binaphthalenedisulfonic acid (MW56-1 to MW56-4)
    Experiments
    profiles.google.com-micha.wolfleMichael Wolfle starting material (see MW56-3) [data=text]897[/data] - heated for a furter 24 h (reaction time 30 h) LCMS (column: C18 waters sunfire, gradient A: water, B acetonitrile + 0.1% formic acid; 0 to 100% B over 15 min, flow 0.2 mL/min) [data=text]911[/data] -> starting material, small amount of PZQ [b]MW56-2:[/b] A solution of [url=http://www.ourexperiment.org/racemic_pzq/1555][b]MW51-1[/b][/url] (18.5 mg, 50.0 µmol, M.W. 370.4 g/mol) and [url=http://www.ourexperiment.org/racemic_pzq/587]1,1’-Binaphthalene-2,2’-disulfonic acid[/url] (2.1 mg, 5.0 µmol, 10 mol%, M.W. 414.5 g/mol) in toluene (1 mL) was stirred for 16 h at 70°C. Product, see: [url=http://www.ourexperiment.org/racemic_pzq/1654][b]MW53-4[/b][/url] LCMS (ESI +): m/z = 339 [hemiacetal] (100), 393 [M+Na] (30), 763 [2M+Na] (30). [data=text]899[/data] - heated for a furter 24 h LCMS: starting material, small amount of product [data=text]913[/data] [b]MW56-3:[/b] A solution of [url=http://www.ourexperiment.org/racemic_pzq/386][b]MW40-1[/b][/url] (21.8 mg, 50.0 µmol, M.W. 436.5 g/mol) and [url=http://www.ourexperiment.org/racemic_pzq/587]1,1’-Binaphthalene-2,2’-disulfonic acid[/url] (2.1 mg, 5.0 µmol, 10 mol%, M.W. 414.5 g/mol) in toluene (1 mL) was stirred for 16 h at 70°C. LCMS (ESI +): m/z = 405 [hemiacetal] (100), 459 [M+Na] (30). [data=text]901[/data] - heated for a furter 24 h [data=text]915[/data][data=text]917[/data] [b]MW56-4:[/b] A solution of [url=http://www.ourexperiment.org/racemic_pzq/1597][b]MW52-1[/b][/url] (21.5 mg, 50.0 µmol, M.W. 430.5 g/mol) and [url=http://www.ourexperiment.org/racemic_pzq/587]1,1’-Binaphthalene-2,2’-disulfonic acid[/url] (2.1 mg, 5.0 µmol, 10 mol%, M.W. 414.5 g/mol) in toluene (1 mL) was stirred for 16 h at 70°C. Product, see: [url=http://www.ourexperiment.org/racemic_pzq//1658][b]MW54-3[/b][/url] LCMS (ESI +): m/z = 399 [hemiacetal] (100), 453 [M+Na] (30). [data=text]903[/data] - heated for a furter 24 h [data=text]919[/data] - Catalyst is sparingly soluble in toluene at rt -> temperature raised to 70°C after 30 min. After 16 h: - TLC (ethyl acetate, 100%; stain:ceric ammonium molybdate) showed no difference between starting material and product (no reaction?) [data]895[/data] - 10 µL of each sample were withdrawn, purified by a small column (silica gel, ethyl acetate, 100%), evaporated and dissolved in acetonitrile (c= 0.05 mg/mL), filtered by a syringe filter and evaluated by LC/MS. LCMS showed mass of the hemiaminals but also the starting material [M+Na] and the dimere of it and only one LC peak in the PDA spectrum -> hemiaminal or fragmentation of the starting material ?? [data]907[/data] After 30 h: [data]905[/data] LCMS of reaction and starting material (fragmentation?) See also: [url=http://www.ourexperiment.org/racemic_pzq/1765]Acid-catalyzed Pictet-Spengler reaction with methanesulfonic acid (MW56-5 to MW56-8)[/url] [b]Results:[/b] -> non-selective reaction for MW56-5 and MW56-6 (unactivated compound) - increasing the catalyst concentration -> almost selective Pictet-Spengler reaction of both dimethoxy-substituted Ugi-intermediates]]>rac-1,1’-Binaphthalene-2,2’-disulfonic acid as a strong Bronsted-acidic catalyst.

    Reaction Scheme


    See also:
  • Attempts to the acid-mediated Pictet-Spengler cyclization of the ‘Ugi intermediate’ MW29 (MW31)
  • Cleavage of the dimethoxy acetal of 2-((2,2-dimethoxyethyl)amino)-N-phenethylacetamide hydrochloride MW7 (MW42-1 to MW42-7)
  • Attempts to the Bronstedt-acid catalysed Pictet-Spengler cyclization using N,N’-bis
  • [3,5-bis(trifluoromethyl)phenyl]thiourea (MW44)
  • Attempts to the Bronstedt-acid catalysed Pictet-Spengler cyclization using BINOL-N-triflyl phosphoramide (MW41)
    and following experiments:
  • Acid-catalyzed Pictet-Spengler reaction with methanesulfonic acid (MW56-5 to MW56-8)
  • Continuation: Acid-catalyzed Pictet-Spengler reaction with methanesulfonic acid (MW56-9 to MW56-12)

    Hazard and Risk Assessment:
  • HRAF MW56.pdf


    Start time: 6:30 pm 14/03/2011
    End time: 9:30 am 16/03/2011

    MW56-1:
    A solution of MW29-4 (18.8 mg, 50.0 µmol, M.W. 376.5 g/mol) and 1,1’-Binaphthalene-2,2’-disulfonic acid (2.1 mg, 5.0 µmol, 10 mol%, M.W. 414.5 g/mol) in toluene (1 mL) was stirred for 16 h at 70°C.
    Product, see: PZQ

    LCMS (ESI +): m/z (%) = 345 [hemiacetal] (100), 399 [M+Na] (30), 775 [2M+Na] (30). -> starting material (see MW56-3)
    Data: LCMS MW56-1 after 16h.pdf

    - heated for a furter 24 h (reaction time 30 h)
    LCMS (column: C18 waters sunfire, gradient A: water, B acetonitrile + 0.1% formic acid; 0 to 100% B over 15 min, flow 0.2 mL/min)
    Data: LCMS MW56-1 (30h).pdf -> starting material, small amount of PZQ

    MW56-2:
    A solution of MW51-1 (18.5 mg, 50.0 µmol, M.W. 370.4 g/mol) and 1,1’-Binaphthalene-2,2’-disulfonic acid (2.1 mg, 5.0 µmol, 10 mol%, M.W. 414.5 g/mol) in toluene (1 mL) was stirred for 16 h at 70°C.
    Product, see: MW53-4
    LCMS (ESI +): m/z = 339 [hemiacetal] (100), 393 [M+Na] (30), 763 [2M+Na] (30). Data: LCMS MW56-2 after 16h.pdf
    - heated for a furter 24 h
    LCMS: starting material, small amount of product
    Data: LCMS MW56-2 (30h).pdf

    MW56-3:
    A solution of MW40-1 (21.8 mg, 50.0 µmol, M.W. 436.5 g/mol) and 1,1’-Binaphthalene-2,2’-disulfonic acid (2.1 mg, 5.0 µmol, 10 mol%, M.W. 414.5 g/mol) in toluene (1 mL) was stirred for 16 h at 70°C.
    LCMS (ESI +): m/z = 405 [hemiacetal] (100), 459 [M+Na] (30). Data: LCMS MW56-3 after 16h.pdf
    - heated for a furter 24 h
    Data: LCMS MW56-3 (30h).pdfData: LCMS MW40-1 starting material for MW56-3.pdf

    MW56-4:
    A solution of MW52-1 (21.5 mg, 50.0 µmol, M.W. 430.5 g/mol) and 1,1’-Binaphthalene-2,2’-disulfonic acid (2.1 mg, 5.0 µmol, 10 mol%, M.W. 414.5 g/mol) in toluene (1 mL) was stirred for 16 h at 70°C.
    Product, see: MW54-3
    LCMS (ESI +): m/z = 399 [hemiacetal] (100), 453 [M+Na] (30). Data: LCMS MW56-4 after 16h.pdf
    - heated for a furter 24 h
    Data: LCMS MW56-4 (30h).pdf

    - Catalyst is sparingly soluble in toluene at rt -> temperature raised to 70°C after 30 min.

    After 16 h:
    - TLC (ethyl acetate, 100%; stain:ceric ammonium molybdate) showed no difference between starting material and product (no reaction?)
    TLC MW56-1 to MW56-4.JPG

    - 10 µL of each sample were withdrawn, purified by a small column (silica gel, ethyl acetate, 100%), evaporated and dissolved in acetonitrile (c= 0.05 mg/mL), filtered by a syringe filter and evaluated by LC/MS.
    LCMS showed mass of the hemiaminals but also the starting material [M+Na] and the dimere of it and only one LC peak in the PDA spectrum
    -> hemiaminal or fragmentation of the starting material ??
    hemiaminal.png


    After 30 h:
    TLC MW56-1 to MW56-8.JPG


    LCMS of reaction and starting material (fragmentation?)

    See also: Acid-catalyzed Pictet-Spengler reaction with methanesulfonic acid (MW56-5 to MW56-8)

    Results:
    -> non-selective reaction for MW56-5 and MW56-6 (unactivated compound) - increasing the catalyst concentration
    -> almost selective Pictet-Spengler reaction of both dimethoxy-substituted Ugi-intermediates
    Linked Entries
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Acid-catalyzed Pictet-Spengler reaction with binaphthalenedisulfonic acid (MW56-1 to MW56-4)ErrorRe: Acid-catalyzed Pictet-Spengler reaction with binaphthalenedisulfonic acid (MW56-1 to MW56-4)That's odd. No reaction at all? I'd expect the acetal to go, even if the cyclization does not. Your follow-up reaction with MeSO3H is the right thing to do, yes.That's odd. No reaction at all? I'd expect the acetal to go, even if the cyclization does not. Your follow-up reaction with MeSO3H is the right thing to do, yes.2011-03-15T10:14:35+00:00