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The photolysis of a-diazosulfones dissolved in alkenes provides sulfonyl-substituted cyclopropanes in high yields.3 This is exemplified by the preparation of l-(^)-methoxyphenylsulfonyl)-2,2,3,3-tetra-methylcyclopropane in 75% yield from ^-methoxybenzenesulfonyl-diazomethane and 2,3-dimethyl-2-butene. A similar addition to trans-2-butene gives (d, J)-l-(^>-methoxyphenylsulfonyl)-<rcm«-2,3-di-methylcyclopropane in 79% yield, resulting from a stereospecifrc cis addition, thus indicating a singlet sulfonylcarbene intermediate.11
Originally, jj-tolylsulfonyldiazomethane was prepared by passing an ethereal solution of its precursor, ethyl N-nitroso -N- (jp -tolylsulfonyl -methyl)carbamate, slowly through a column of alumina.12 This procedure, which results in yields about 10% higher, is convenient only for small-scale preparations, up to a maximum of 5 g. of ^-tolylsulfonyl-diazomethane. The present modification is due to Middelbos.13
The conversion of nitrosocarbamates into a-diazosulfones is effected also with certain bases, notably by aqueous potassium hydroxide.12 Potassium hydroxide, however, causes rapid decomposition of p-tolyl-sulfonyldiazomethane. Alumina is thought to act as a solid base and does not cause significant decomposition.
Other syntheses of ^-tolylsulfonyldiazomethane have been worked out. Reaction of p-carboxybenzenesulfonyl azide and ammonia with p-tolylsulfonylacetaldehyde hemihydrate or p-tolylsulfonylacetalde-hyde enol acetate gives p-tolylsulfonyldiazomethane in yields of 73 and 58%, respectively.14 Furthermore, ^-tolylsulfonyldiazomethane is obtained in 60% yield by reaction of p-tolylsulfonylmethylenetriphenyl-phosphorane and either p-tolylsulfonyl azide or p-carboxybenzene-sulfonyl azide.14 A method similar to the first of these syntheses has been used for preparation of (alkyl- or arylsulfonyl)phenyldiazo-methanes. However, the present procedure has the advantage of being simple and easily scaled-up, and uses readily available, inexpensive starting materials.
An alternative to the synthesis of arylsulfonyhnethylcarbamates by the Mannich condensation as described here,15 is the Curtius rearrangement of the hydrazides of arylsulfonylacetic acids.16
1. Department of Organic Chemistry, Groningen University, Groningen, The Netherlands.
2. W. E. Truce and F. E. Roberts, J. Org. Chem., 28, 693 (1963).
3. P. Oxley, M. W. Partridge, T. D. Robson, and W. F. Short, J. Chem. Soc., 763 (1946).
4. J. R. Morton and H. W. Wilcox, Inorg. Syn., 4, 48 (1953).
5. A. M. van Leusen and J. Strating, Quart. Rep. Sulfur Chem., 5, 67 (1970).
6. F. Kurzer and J. R. Powell, Org. Syn.t Coll. Vol. 4, 934 (1963).
7. J. Strating and J. Reitsema, Âåñ. Trav. Chim. Pays-Bas, 85, 421 (1966).
8. J. C. Jagt, I. van Buuren, J. Strating, and A. M. van Leusen, Synthetic Commun., 4, 311 (1974).
9. J. B. F. N. Engberts and B. Zwanenburg, Tetrahedron Lett831 (1967).
10. B. Zwanenburg, W. Middelbos, G. J. K. Hemke, and J. Strating, Bee. Trav. Chim. Pays-Bas, 90, 429 (1971); cf. W. Middelbos, B. Zwanenburg, and J. Strating, Rec. Trav. Chim. Pays-Bas, 90, 435 (1971).
11. A. M. van Leusen, R. J. Mulder, and J. Strating, Rec. Trav. Chim. Pays-Bas, 86, 225 (1967).
12. A. M. van Leusen and J. Strating, Rec. Trav. Chim. Pays-Bas, 84, 151 (1965).
13. W. Middelbos, Ph.D. Thesis, Groningen University, 1971.
14. A. M. van Leusen, B. A. Reith, and D. van Leusen, Tetrahedron, 31, 597 (1975).
15. J. B. F. N. Engberts and J. Strating, Rec. Trav. Chim. Pays-Bas, 84, 942 (1965).
16. A. M. van Leusen and J. Strating, Rec. Trav. Chim. Pays-Bas, 84, 140 (1965).
p-TOLYLSULFONYLMETHYL ISOCYANIDE [Benzene, l-((isocyanomethyl) sulfonyl) - 4 - methyl - ]
Submitted by Â. E. Hoogenboom, Î. H. Oldenziel, and A. M. van Leusen1
Checked by Tebesa Y. L. Chan and S. SIasamune
Caution! The reaction should be conducted in a well-ventilated fume hood.
A. N-(p-Tolylsulfonylmethyl)formamide [Formamide, l$-(4:-methyl-
phenylsulfonylmethyl)-].2 A 3-1., three-necked, round-bottomed flask, equipped with a mechanical stirrer, a condenser, and a thermometer, is charged with 267 g. (1.5 moles) of sodium p-toluenesulfinate (Note 1). After addition of 750 ml. of water, 350 ml. (378 g.) of a 34-37% solution of formaldehyde (ca. 4.4 moles) (Note 2), 600 ml. (680 g., 16 moles) of formamide (Note 3), and 200 ml. (244 g., 5.3 moles) of formic acid (Note 4), the stirred reaction mixture is heated at 90°. The sodium jj-toluenesulfinate dissolves during heating, and the clear solution is kept at 90-95° for 2 hours (Note 5). The reaction mixture is cooled to room temperature in an ice-salt bath with continued stirring and then further cooled overnight in a freezer at — 20°. The white solid (Note 6) is collected by suction filtration. It is washed thoroughly in a beaker by stirring with three 250-ml. portions of ice water. The product is dried under reduced pressure over phosphorus pentoxide at 70° (Note 7) to provide 134-150 g. (42-47%) of crude N-(p-tolylsulfonylmethy 1)-formamide, m.p. 106-110° (Note 8). This product is sufficiently pure to be used directly in the next step of the reaction.