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1
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84986470846
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Tiazofurin is the generic name approved by the United States Adopted Names Council. Selenazofurin is a common name used to identify the selenium analog of tiazofurin.
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2
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0017328408
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(1977)
J. Med. Chem.
, vol.20
, pp. 256
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Srivastava, P.C.1
Pickering, M.V.2
Allen, L.B.3
Streeter, D.G.4
Campbell, M.T.5
Witkowski, J.T.6
Sidwell, R.W.7
Robins, R.K.8
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4
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0020633883
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(1983)
Antimicrob. Agents Chemother.
, vol.24
, pp. 353
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Kirsi, J.J.1
North, J.A.2
McKernan, P.A.3
Murry, B.K.4
Canonico, P.G.5
Huggins, J.W.6
Srivastava, P.C.7
Robins, R.K.8
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9
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84986429456
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Chem. Abstr.
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(1983)
, pp. 38785s
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10
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84986519729
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Tlc examination of the reaction mixture clearly shows that the α‐anomer of 5 is not present. The major decomposition product, being less polar than 5, is likely the benzoate elimination product, ethyl 2‐[5‐(benzoyloxy)methyl]furan‐2‐yl‐4‐selenazolecarboxylate. Ethyl 2‐[5‐(benzoyloxy)methyl]furan‐2‐yl‐4‐thiazolecarboxylate is a major decomposition product in previous tiazofurin syntheses [2,9].
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12
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84986445470
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In several experiments the reaction, after treatment with ethyl bromopyruvate, was filtered through filter aid prior to neutralization without any apparent loss in the yield in the isolated β‐anomer 6.
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20
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84986487415
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In vitro L1210 screening data was kindly provided by Dr. J. Shillis and Ms. C. Pinter of Warner‐Lambert/Parke‐Davis Pharmaceutical Research Division, Cancer Chemotherapy Department.
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21
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84986445483
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Tlc, silica gel/toluene‐ethyl acetate (5:1), indicates a very clean and complete conversion of 3 to 4. Spots were detected by anisaldehyde:methanol:sulfuric acid spray (0.1:10:1) followed by heating; on charring in this manner 1‐O‐acetylsugar 3 is a brownish‐red spot and cyanide sugar 4 is a blue spot.
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22
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84986522152
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Considerable volume reduction may be realized by using a suspension of cyanide sugar 4 in ethanol; the reaction appears to proceed satisfactorily as such. Passing hydrogen selenide through a solution of 4 at 35° provides a major side product, possibly the furan‐2‐yl‐selenazole elimination product [2,9].
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23
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84986532003
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A 12‐liter, round‐bottom flask was equipped with an air stirrer, inlet dispersion tube, outlet dispersion tube and thermometer, and septum for sampling. The outlet dispersion tube vented exhaust gases through a 4‐liter filter flask of ice water (3 l). Hydrogen selenide is quite soluble in cold water (3.77 g in l ml of 4° water). (Trapping hydrogen selenide in an alkaline solution is not practical due to the extreme tendency for alkali metal selenides to clog the outlet tubes). After the gas has been trapped in ice water, the red suspension (polymeric selenium?) is made basic with 50% sodium hydroxide solution and placed in waste bottles.
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24
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84986519832
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Hydrogen selenide (2 × 14 ml, MLB lecture bottle, 350 valve outlet, 0.5 pound) was purchased from Synthatron Corporation, Parsippany, New Jersey.
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25
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84986481791
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Argon flow was stopped during hydrogen selenide treatment. Under these conditions, hydrogen selenide was completely absorbed in the ethanol is noted by the lack of decomposed hydrogen selenide (red color) in the exhaust line and ice water trap. From a safety point of view, it is certainly desirable to contain all hydrogen selenide in the reaction solvent.
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26
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84986487397
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Silica gel/chloroform‐ethyl acetate (10:1) tlc was used. During several runs, a rather heavy precipitate of selenocarboxamide 5 was formed.
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27
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84986532021
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Refiltration through celite may be required at this stage to remove additional polymeric selenium.
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28
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84986519842
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Silica gel/chloroform‐ethyl acetate (10:1) tlc was used.
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29
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84986532024
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The methanol was heated to approximately 50° to solubilize the syrup. The ammonolysis of selenazole 6 to selenazofurin (1) may also be realized by keeping the pressure vessel at ambient temperature for 48–72 hours.
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30
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84986519847
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Deblocking of selenazole 6 under these conditions provides both benzamide and methyl benzoate as side products which are essentially completely removed by the extraction procedure.
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31
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84986519826
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It should be possible to purify this foam at this stage by crystallization, however on a relatively small run as this, a short column procedure before crystallization is desirable.
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32
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84986522132
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An impurity which chars lightly, is not detected by ultraviolet light, but is visible in iodine vapor, appears just below the major product in the tlc.
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33
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84986533089
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2‐Propanol‐methanol (10:1) is a more appropriate solvent system for recrystallization of larger amounts of crude material.
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34
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84986527978
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This yield is based on the 79% purity of the starting syrup material.
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