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Volumn 75, Issue 13, 2010, Pages 4463-4471

Synthesis of a histamine H 3 receptor antagonist - Manipulation of hydroxyproline stereochemistry, desymmetrization of homopiperazine, and nonextractive sodium triacetoxyborohydride reaction workup

Author keywords

[No Author keywords available]

Indexed keywords

[CARBONYL; COST-OF-GOODS; DESYM-METRIZATION; L-PROLINE; MITSUNOBU REACTIONS; NATURALLY OCCURRING; RECEPTOR ANTAGONISTS; ROUTE SELECTION; SECOND GENERATION; SODIUM TRIACETOXYBOROHYDRIDE; STEREOGENIC CENTERS; WATER SOLUBILITIES;

EID: 77954104443     PISSN: 00223263     EISSN: 15206904     Source Type: Journal    
DOI: 10.1021/jo100629z     Document Type: Article
Times cited : (13)

References (41)
  • 7
    • 77954121139 scopus 로고    scopus 로고
    • For a case with a R configuration at C-2 (starting from cis -4-hydroxy- d -proline), see:;;;; WO 030757
    • For a case with a R configuration at C-2 (starting from cis -4-hydroxy- d -proline), see: Bradbury, R. H.; Halsall, C. T.; Hennequin, L. F. A.; Kettle, J. G.; Plowright, A. WO 030757, 2005.
    • (2005)
    • Bradbury, R.H.1    Halsall, C.T.2    Hennequin, L.F.A.3    Kettle, J.G.4    Plowright, A.5
  • 10
    • 77954124539 scopus 로고    scopus 로고
    • Within this class of pharmaceuticals, meropenem is the most famous. Process patents for the key hydroxy proline piece include:;;;; Chinese Patent 101033209
    • Within this class of pharmaceuticals, meropenem is the most famous. Process patents for the key hydroxy proline piece include: Zhang, F.; Ju, Y.; Pan, H.; Wang, G.; Xie, M. Chinese Patent 101033209, 2007.
    • (2007)
    • Zhang, F.1    Ju, Y.2    Pan, H.3    Wang, G.4    Xie, M.5
  • 17
    • 84855617598 scopus 로고    scopus 로고
    • Standard Sigma-Aldrich pricing: N -Boc-homopiperazine, $3180/mol; homopiperazine $124/mol
    • Standard Sigma-Aldrich pricing: N -Boc-homopiperazine, $3180/mol; homopiperazine $124/mol.
  • 21
    • 84855637380 scopus 로고    scopus 로고
    • We were able to purchase 1 kg of N -acetylated 4 for less than $1/g
    • We were able to purchase 1 kg of N -acetylated 4 for less than $1/g.
  • 22
    • 77954095292 scopus 로고    scopus 로고
    • AS-H column, 85/15 hexanes/ethanol, 1 mL min flow rate, (S, S) enantiomer retention time 39 min, (R, R) enantiomer 42 min
    • AS-H column, 85/15 hexanes/ethanol, 1 mL min flow rate, (S, S) enantiomer retention time 39 min, (R, R) enantiomer 42 min.
  • 28
    • 77954134250 scopus 로고    scopus 로고
    • As shown in Figures 3 and 4, initial medicinal chemistry efforts utilized the di-HCl salt of cyclobutylhomopiperazine for the synthesis of 1. We found the ditosylate to be less hygroscopic and, thus, more suitable for benchtop handling. See the Experimental Section for details on the synthesis of cyclobutylhomopiperazine ditosylate
    • As shown in Figures 3 and 4, initial medicinal chemistry efforts utilized the di-HCl salt of cyclobutylhomopiperazine for the synthesis of 1. We found the ditosylate to be less hygroscopic and, thus, more suitable for benchtop handling. See the Experimental Section for details on the synthesis of cyclobutylhomopiperazine ditosylate.
  • 31
    • 77954095850 scopus 로고    scopus 로고
    • See the Supporting Information for characterization related to the crude mixture 8 and 7
    • See the Supporting Information for characterization related to the crude mixture 8 and 7.
  • 34
    • 0037505335 scopus 로고    scopus 로고
    • For an example of a polymer-supported variant of triacetoxyborohydride, which can be utilized in reductions that require no aqueous workup
    • For an example of a polymer-supported variant of triacetoxyborohydride, which can be utilized in reductions that require no aqueous workup, see: Bhattacharyya, S.; Rana, S.; Gooding, O. W.; Labadie, J. Tetrahedron Lett. 2003, 44, 4957-4960
    • (2003) Tetrahedron Lett. , vol.44 , pp. 4957-4960
    • Bhattacharyya, S.1    Rana, S.2    Gooding, O.W.3    Labadie, J.4
  • 35
    • 0004258422 scopus 로고
    • The CRC Handbook, 72nd ed. reports a solubility of 8 mg/100 mL of boric acid in diethyl ether and slight solubility of sodium acetate in alcohol.; CRC Press: Boca Raton
    • The CRC Handbook, 72nd ed. reports a solubility of 8 mg/100 mL of boric acid in diethyl ether and slight solubility of sodium acetate in alcohol. The CRC Handbook; CRC Press: Boca Raton, 1991
    • (1991) The CRC Handbook
  • 36
    • 77954123774 scopus 로고    scopus 로고
    • We theorized that a minimum of 1/7 equiv of anhydrous magnesium sulfate (relative to water) was required for the quench, as magnesium sulfate forms a heptahydrate with water
    • We theorized that a minimum of 1/7 equiv of anhydrous magnesium sulfate (relative to water) was required for the quench, as magnesium sulfate forms a heptahydrate with water.
  • 37
    • 77954131891 scopus 로고    scopus 로고
    • Because our final step ultimately employed Mitsunobu conditions, complete removal of the potentially nucleophilic acetate was necessary. Peak shaving to remove minor impurities resulted in the substantial decrease in yield from crude to purified 6
    • Because our final step ultimately employed Mitsunobu conditions, complete removal of the potentially nucleophilic acetate was necessary. Peak shaving to remove minor impurities resulted in the substantial decrease in yield from crude to purified 6.
  • 38
    • 62349129313 scopus 로고    scopus 로고
    • The actual structure(s) of the elimination byproduct(s) was not proven. Elimination reactions at C4 of various proline analogues have been shown to provide both potential product regioisomers
    • The actual structure(s) of the elimination byproduct(s) was not proven. Elimination reactions at C4 of various proline analogues have been shown to provide both potential product regioisomers. Zhao, X.; Zhuang, W.; Fang, D.; Xue, X.; Zhou, J. Synlett 2009, 779-782
    • (2009) Synlett , pp. 779-782
    • Zhao, X.1    Zhuang, W.2    Fang, D.3    Xue, X.4    Zhou, J.5
  • 40
    • 77954105933 scopus 로고    scopus 로고
    • Similar reactions utilizing the corresponding tosylate and nosylate were equally fruitless
    • Similar reactions utilizing the corresponding tosylate and nosylate were equally fruitless.
  • 41
    • 84855637379 scopus 로고    scopus 로고
    • 2/methanol with 0.2% TEA and then holding for 20 min, 2 mL/min flow rate, (2 R, 4S) isomer retention time 5.3 min, (2 R, 4 R) isomer retention time 11.5 min, (2 S, 4 S) isomer retention time 24.3 min, (2 S, 4 R) isomer retention time 31.6 min
    • 2/methanol with 0.2% TEA and then holding for 20 min, 2 mL/min flow rate, (2 R, 4S) isomer retention time 5.3 min, (2 R, 4 R) isomer retention time 11.5 min, (2 S, 4 S) isomer retention time 24.3 min, (2 S, 4 R) isomer retention time 31.6 min.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.