in black and white
Main menu
Home About us Share a book
Biology Business Chemistry Computers Culture Economics Fiction Games Guide History Management Mathematical Medicine Mental Fitnes Physics Psychology Scince Sport Technics

Organic Synthess - Johnson S.K.

Johnson S.K., Brossi A., Seebach D. Organic Synthess - Michigan, 1977. - 138 p.
Download (direct link): organicsynthess1977.pdf
Previous << 1 .. 20 21 22 23 24 25 < 26 > 27 28 29 30 31 32 .. 56 >> Next

1. Department of Chemistry, The Ohio State University, Columbus, Ohio 43210.
2. L. P. Kuhn, J. Amer. Chem. Soc., 74, 2492 (1952).
3. G. A. Haggis and L. N. Owen, J. Chem. Soc., 389 (1953).
4. L. P. Kuhn, P. von R. Schleyer, W. F. Baitinger, and L. Eberson, J. Amer. Cftem. Soc., SB, 660 (1964).
5. H. Bohme, Org. Syn. CoU. Vol. 3, 619 (1955).
6. S. F. Birch, R. A. Dean, and E. V. Whitehead, J. Org. Chem., 19, 1449 (1954).
7. R. Srinivasan, J. Amer. Chem. Soc., 84, 4141 (1962).
8. K. J. Crowley, Tetrahedron, 21, 1001 (1965).
9. E. H. White and J. P. Anhalt, Tetrahedron Lett., 3937 (1965).
19. C. D. Gutsche and D. Redmore, “Carbocyclic Ring Expansion Reactions,” Academic Press, New York, 1968, p. 111.
11. P. E. Eaton, Accounts Chem. Âåÿ., 1, 50 (1968).
12. W. G. Gensler, J. J. Langone, and Ì. B. Floyd, J. Amer. Chem. Soc., 93, 3828 (1971).
13. H. H. Freedman and A. M. Frantz, J. Amer. Chem. Soc., 84, 4165 (1962).
14. R. M. Dodson and A. G. Zielska, J. Org. Chem., 32, 28 (1967).
15. Y. Hoaokawa and I. Moritani, Tetrahedron Lett., 3021 (1969).
16. M. S. Newman and G. Kaugars, J. Org. Chem., SO, 3295 (1965).
17. J. M. Photis and L. A. Paquette, J. Amer. Chem. Soc., 96, 4715 (1974).
18. L. A. Paquette, J. S. Ward, R. A. Boggs, and W. B. Farnham, J. Amer. Chem. Soc., 97, 1101 (1975).
19. L. A. Paquette, J. M. Photis, Ê. B. Gifkens, and J. Clardy, J. Amer. Chem. Soc., 97, 3536 (1975).
29. L. A. Paquette, J. M. Photis, and G. D. Ewing, J. Amer. Chem. Soc. ,97, 3538 (1975).
21. L. A. Paquette, “Mechanisms of Molecular Migrations,” Vol. I, B. S. Thyagarajan, Ed., Interscience, New York, 1968, pp. 121-156.
22. R. H. Mitchell and V. Boekelheide, J. Amer. Chem. Soc., 96, 1547 (1974), and references cited therein.
In a 1-1., three-necked, round-bottomed flask equipped with a calcium chloride drying tube, a mechanical stirrer, and a ground-glass stopper are placed 28.2 g. (0.184 mole) of freshly distilled methyl bromoacetate, 600 till, of anhydrous iV,jV-dimethylacetamide (Note 1), and 20.0 g. (0.168 mole) of methyl nitroacetate (Note 2). The solution is stirred •vigorously while 146 ml. (0.168 mole) of 1.15N sodium methoxide in
DIMETHYL NITROSUCCINATE [Butanedioic acid, 2-nitro-, dimethyl ester] COaCH3
Submitted by S. Zen and E. Kaji1 Checked by M. Braun and G. BiiCHi
1. Procedure
methanol is added in one portion. The resulting light-yellow suspension is stirred for an additional 16 hours at room temperature during which time it changes into a clear yellow solution.
After dilution with 200 ml. of benzene, the solution is transferred to a 2-1. separatory funnel containing 800 ml. of ice water and shaken thoroughly. The aqueous layer is separated, acidified to pH 3-4 with
2-3 ml. of concentrated hydrochloric acid, and extracted with three 100-ml. portions of benzene. All the organic layers are then combined and dried over anhydrous sodium sulfate. Filtration and concentration of the solution with a rotary evaporator, followed by exposure to high vacuum for 2-3 hours, affords 17.3-19.3 g. of the crude product (Note 3). Low-boiling impurities are removed by vacuum distillation (Note 4), the residual oil (14-15 g.) is transferred to a 50-ml. flask equipped with a short-path distillation apparatus, and vacuum distillation is continued. A forerun is taken until no rise in boiling point is observed, and then 7.2-8.5 g. (23-27%) of dimethyl nitrosuccinate is collected as a colorless oil, b.p. 85° (0.07 mm.), n20D 1.4441 (Note 5).
2. Notes
1. AT,IV-dimethylacetamide was treated with molecular sieves for
2 days, decanted, and distilled under reduced pressure, b.p. 85° (30 mm.), before use.
2. Methyl nitroacetate was prepared by the method of Zen and coworkers.2 It should be distilled before use.
3. Gas chromatographic analysis of the crude mixture (SE-30 on Chromosorb W, 1 m., 150°) showed the presence of some low-boiling materials (including unreacted methyl nitroacetate) and a significant amount of the doubly alkylated by-product, trimethyl 2-nitro-l,2,3-propanetricarboxylate.
4. The bath temperature should be maintained below 70-75°. Distillation was carried out using a Claisen head, and the receiving flasks were immersed in ice.
The checkers found it convenient to omit this distillation and the subsequent transfer. Instead the crude product was placed in a 25-ml. flask and carefully distilled at 0.07 mm. The bath temperature was raised slowly, and a forerun was collected until the boiling point stabilized.
5. The distilled product was determined by the checkers to be 85-90% pure (gas chromatographic analysis), the major impurity being
the doubly alkylated by-product. Purity can be increased to 95% by redistillation. The checkers found that conducting the experiment on a ? scale resulted in increased yield (34%) and purity (90-93%) of once-distilled product.
Previous << 1 .. 20 21 22 23 24 25 < 26 > 27 28 29 30 31 32 .. 56 >> Next