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Organic Synthess - Johnson S.K.

Johnson S.K., Brossi A., Seebach D. Organic Synthess - Michigan, 1977. - 138 p.
Download (direct link): organicsynthess1977.pdf
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3. Discussion
y-Tolylsulfonylmethyl isocyanide was originally obtained by irradiation of p-tolylsulfonyldiazomethane3 in liquid hydrogen cyanide.4 This isocyanide represents a group of sulfonylmethyl isocyanides, most of which have been prepared, as in the present procedure, by dehydration of the corresponding formamides.4,5 jp-Tolylsulfonylmethyl isocyanide has also been prepared by reaction of p-tolylsulfonyl fluoride with isocyanomethyllithium.4 6 The advantages of the present dehydration method are twofold: (1) it is a simple procedure using readily available and inexpensive starting materials and (2) the use of the foulsmelling methyl isocyanide is avoided.
p-Tolylsulfonylmethyl isocyanide is a useful and versatile reagent in
organic chemistry. It has been used for the synthesis of several azole ring systems by base-induced addition of its їN=C moiety to various
C=0, 0=N, C=S, C=C, and N=N containing substrates. Thus oxazoles,7 imidazoles,8 thiazoles,9 pyrroles,10 and 1,2,4-triazoles11 have been prepared, respectively. Furthermore, p-tolylsulfonylmethyl isocyanide has found use in a one-step conversion of ketones into cyanides12-14 and in a two-step synthesis of a-hydroxyaldehydes from ketones.15
1. Department of Organic Chemistry, Groningen University, Zemikelaan, Groningen, The Netherlands.
2. T. Olijnsma, J. B. F. N. Engberts, and J. Strating, . Trav, Chim. Paye-Bas, 91, 209 (1972).
3. A. M. van Leusen and J. Strating, Org.Syn., 57, 95 (1977); Review: A. M. vanLeusen and J. Strating, Quart. Rep. Sulfur Chem., 5, 67 (1970).
4. A. M. van Leusen, G. J. M. Boerma, R. B. Helmholdt, H. Siderius, and J. Strating, Tetrahedron Lett., 2367 (1972); A. M. van Leusen, R. J. Bouma, and O. Possel, Tetrahedron Lett., 3487 (1975).
5. H. Bohme and G. Fucha, Chem. Ber., 103, 2775 (1970).
6. U. Schollkopf, R. Schroder, and E. Blume, Justus Liebigs Ann. Chem., 766, 130 (1972).
7. A. M. van Leusen, . E. Hoogenboom, and H. Siderius, Tetrahedron Lett., 2369
8. A. M. van Leusen and . H. Oldenziel, Tetrahedron Lett., 2373 (1972); A. M. van Louson, J. Wildeman, and . H. Oldenziel, J. Org. Chem., 42, 1153 (1977).
9. . H. Oldenziel and A. M. van Leusen, Tetrahedron Lett., 2777 (1972).
10. A. M, van Leusen, H. Siderius, . E. Hoogenboom, and D. van Leusen, Tetrahedron Lett., 5337 (1972).
11. A. M. van Leusen, B.E. Hoogenboom, and H. A. Houwing, *7. Org. Chem., 41, 711 (1976).
12. . H. Oldenziel and A. M. van Leusen, Tetrahedron Lett., 1357 (1973).
13. . H. Oldenziel, J. Wildeman, and A. M. van Leusen, Org. Syn., 57, 8 (1977);
. H. Oldenziel and A. M. van Leusen, Synthetic Commun., 2, 281 (1972).
14. J. R. Bull and A. Tuinman, Tetrahedron, 31, 2151 (1975).
15. . H. Oldenziel and A. M. van Leusen, Tetrahedron Lett., 167 (1974).
[Iron, tricarbonyl[(2,3,4,5-r))-2,4-cyclohexadien-l-one] and Iron(l + ), tricarbonyl[(l,2,3,4,5-))-2-methoxy-2,4-cyclohexadien-l-yl] hexafluorophosphate (1 )]
+ (CeH5)3C BF

D- Vr Fe(CO)3 + H20
E. I 'V + NHf PFf
BF? 4 8
^4r^Fe(C0)3 ']/ +
+ (CeH5)3CH
n.Fe(C0)3 BFf
+ CH3OH + HBF4
Fe(C0)3 OCH3
V + NHf* BF?
Submitted by A. J. Birch and . B. Chamberlain1 Checked by SusuMtr Kamata, Tstjtomtj Aoki, and Watabu Naoata
1. Procedure
Caution! Parts A and must be conducted in an efficient hood to prevent exposure to ammonia, iron pentacarbonyl, and carbon monoxide.
A. 1 -Methoxy-1,4:-cyclohexadiene. A 3-1., three-necked, round-bottomed flask equipped with an inlet tube, mechanical stirrer, and dry-ice condenser (cooled with acetone-dry ice) fitted with a drying tube, is charged with 150 ml. of tetrahydrofuran, 250 ml. of (ert-butyl alcohol, and 50 g. (0.46 mole) of anisole (Note 1). About 1.51. of dried liquid ammonia (Note 2) is distilled into the reaction vessel from a steam bath. Lithium (11.5 g., 1.66 g.-atoms) (Notes 3, 4) is added cautiously with stirring and, when the addition is complete, the stirring is continued for 1 hour with refluxing. The blue color is discharged by cautiously adding methanol dropwise (about 100 ml. is required); then 750 ml. of water is carefully added. The excess ammonia is allowed to evaporate overnight, more water is added to dissolve the lithium salts, and the mixture is extracted three times with 100-ml. portions of petroleum ether (b.p. 30-40) (Note 5). The combined extracts are washed four times with 75-ml. portions of water to remove iert-butyl alcohol and methanol, dried over anhydrous magnesium sulfate, and the solvent is removed through a 30-cm. Vigreux column (Note 6) under reduced pressure (20 mm.). The residue on distillation yields 1-methoxy-1,4-cyclohexadiene (38-40 g., about 75%) (Notes 7, 8), b.p. 40 (20 mm.).
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