J. Org. Chem. 1983,48, 611-612 solution of another Grignard reagent (20 mmol) [or an ether solution (10 mL) of LiAlH4 or LiA1D4 (6 mmol) and AlC13 (6 mmol)] was added at -60 "C over a period of 30 min. After 3 h was added, and the of stirring, lithium powder (0.42 g, 60 "01) mixture was stirred at -60 OC for an additional 2 h and then allowed to wann up to room temperature overnight. The resulting solution was hydrolyzed successively with water and aqueous hydrochloric acid, and it was extracted with ether. The organic layer was dried over anhydrous sodium sulfate and carefully distilled to afford the corresponding olefin 2, 3, or 4. In the case of the obtention of compounds 5 and 6, after the addition of lithium powder a bubbler containing a solution of bromine (3.19 g, 40 mmol) in CC14 (30 mL) was connected to the reaction flask. After 2 h of stirring at -60 "C the mixture was allowed to warm up to room temperature overnight, and it was hydrolyzed with water and aqueous hydrochloric acid. The resulting solution was heated at 50 "C in a water bath, with a stream of argon being passed through the liquid. The CC14 solution contained in the bubbler was washed successively with an aqueous solution of potassium carbonate and water and extracted with ether. The organic layer was dried over anhydrous sodium sulfate, and the solvents were removed at 15 torr. The residue was distilled to afford the vic-dibromo compound 5 or 6. Registry No. 1 (R' = R2 = H), 79-04-9;1 (R' = H R2 = Me), 7623-09-8; 1 (R' = H; R2 = Et), 7623-11-2; 1 (R', R2 = (CHZ)S), 52831-99-9; 1 (R' = R2 = Me), 13222-26-9;2a, 84394-38-7; 2b, 30479-99-3;2c, 42104-34-7;(E)-2d,84394-39-8; (Z)-2d, 8439440-1; (E)-2e,84394-41-2; (Z)-2e, 84394-42-3;(E)-2f,60820-20-4;(Z)-2f, 84416-62-6; (E)-2g, 84394-43-4; (Z)-2g, 84394-44-5; (E)-2h, 84394-45-6; (Z)-2h, 84394-46-7; (E)-2i, 84394-47-8; (Z)-2i, 84394-48-9; (E)-2j, 84394-49-0; (Z)-2j, 84394-50-3; (E)-2k, 84394-51-4; (Z)-2k, 84394-52-5; (E)-21, 84394-53-6; (27-21, 84394-54-7; (E)-2m, 84394-55-8; (Z)-2m, 84394-56-9; (E)-2n, 84394-57-0; (Z)-%n, 84394-58-1; 20, 84394-59-2; 2p, 84394-60-5; ( E ) - ~ c14686-13-6; , ( Z ) - ~ C6443-92-1; , (E)-3d, 2114-41-2;(Z)-3d, 37490-34-9; (E)-&, 935-00-2; (Z)-&,15324-90-0; (E)-3f, 14686-147; (Z)-3f, 7642-10-6;(E)-3g,14919-01-8;(Z)-3g, 14850-22-7;(E)-3h, 66225-20-5; (Z)-3h, 66225-19-2; (E)-3i, 65457-68-3; (Z)-3i, 65457-67-2;(E)-3j, 51795-73-4;(Z)-3j, 37549-95-4;3k, 2738-19-4; 31,627-97-4;3m, 4489-84-3;(E)&, 8439464-9; (Z)-4c,84394-65-0; (E)-4d, 84394-66-1;(Z)-4d, 84394-67-2;(E)-&, 84394-68-3;(Z)-4e, 84394-69-4; (E)-4f, 84394-70-7; (Z)-4f, 84394-71-8; (E)-4g, 84394-72-9; (Z)-4g, 84394-73-0; (E)-4h, 84394-74-1; (Z)-4h, 84394-75-2; (E)-4i,84394-76-3; (2)-4i, 84394-77-4;4j, 84394-78-5; 5a, 3234-49-9;(R*,S*)-5b,58608-84-7;(R*,R*)-Sb,58608-83-6;6a, 84394-61-6;(R*,S*)-Gb,84394-62-7;(R*&*)-Sb, 84394-63-8;allyl bromide, 106-95-6;n-PrBr, 106-94-5;n-BuBr, 109-65-9;i-BuBr, 78-77-3;PhCH2Br,100-39-0;CyBr, 108-85-0; EtBr, 74-96-4; MeBr, 74-83-9; Li, 7439-93-2; LiA1H4, 16853-85-3; AlC13, 7446-70-0. Supplementary Material Available: Spectral and analytical data for compounds 2a-i, 2k-p, 3i, 6a,b, and 4c-j (7 pages). Ordering information is given on any current masthead page.
Synthesis of Novel Energetic Compounds. 5. Use of Acetyl Azide as an "Azidation Agent"' Milton B. Frankel* and Dean 0. Woolery Rocketdyne Division, Rockwell International, Canoga Park, California 91304 Received August 17, 1982
l-(Azidomethyl)-3,5,7-trinitro-1,3,5,7-tetrazacycloo~e (3) is of particular interest to our continuing studies on the synthesis of energetic azido compounds because of its
structural relationship to the well-known high explosive 1,3,5,7-tetranitro-l,3,5,7-tetrazacyclooctane(HMX). (1) (a) For the previous paper in this series, see: Wilson, E. R.; Frankel, M. B. J. Chem. Eng. Data 1982,27, 472. (b) We are indebted to the Air Force Office of Scientific Research for support of this work.
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Previous workers2were unsuccessful in preparing 3 by the classical method of treatment of the correspondingacetate (1) with sodium azide. I t was apparent that under the basic conditions of the nucleophilic reaction with sodium azide, decomposition of the eight-membered ring was occurring. Therefore, it was concluded that the best chance for success with this reaction would be under nonbasic conditions. Dunning and Dunning3 have reported that treatment of l-(methoxymethyl)-3,5-dinitro-l,3,5-triazacyclohexane with acetyl chloride and acetyl bromide gave 1-(chloromethyl)-3,5-dinitro-1,3,5-triazacyclohexane and 1-(bromomethyl)-3,5-dinitro-l,3,5-triazacyclohexane, respectively. This chemistry was applied to our current work on the eight-membered-ring derivatives. Treatment of 1 with acetyl bromide gave a quantative yield of 1-(bromomethyl)-3,5,7-trinitro-1,3,5,7-tetracyclooctane (2). Attempts to convert 2 to 3 with sodium azide were unsuccessful. A novel method was developed for the conversion of 2 to 3 with acetyl azide as the azidation agent (eq 1). The
ioz
CH,-N+H, I
02"
I
I
I
NNO,
I
CH,-N-~H,
I
I
CHz-N-CH, I
I
CH COBr
3 0,"
I
CH$ON3
I
I
I
CH,-N-CH,
CH20Ac
I
I
NNO,
I
CH2Br
2
1
poz I
CHz-N-CH,
I
I I
"0,
CHz-N-CHZ
(1)
I
CH2N3
3
acetyl azide is generated in situ in methylene chloride solution at 5 "C and is reacted with 2 in a heterogeneous reaction at 10-15 "C. The low temperature is required since acetyl azide starts to decompose at about 40 "C to form methyl isocyanate via the Curtius reaction. The conversion of 2 to 3 was achieved in 79% yield. The use of acetyl azide as an azidation agent provides a unique method for the synthesis of the azido compound under nonbasic conditions. The method appears to application only to labile methylol amine derivatives, but the generality of the reaction has not been determined.
Experimental Section Caution. The polynitro compounds described in this paper are explosives and should be handled with due care. In particular, reactions should be run on a small scale behind adequate shielding. Personnel should be equipped with safety glasses and fire-retardant laboratory coats. The elemental analyses were performed by Galbraith Laboratories, hc., Knoxville, TN. Satisfactory analyses were obtained for all elements except oxygen. The melting points are uncorrected. IR spectra were taken with a Perkin-Elmer 137 Infracord, and HPLC analyses were determined with a Waters HPLC unit. l-(Bromomethyl)-3,5,7-trinitro-l,3,5,7-tetrazacyclooctane (2). Acetyl bromide (500 g, 4.07 mol) was cooled to -10 "C under N2 1 (98.3 g, 0.304 mol) was added, and the mixture was stirred (2) Bell, J. A.; Dunstan, I. J. Chem. SOC. C 1969, 862-869. (3) Dunning, K. W.; Dunning, W. J. J. Chem. SOC.1950, 2925.
0 1983 American Chemical Society
J. Org. Chem.
612
1983, 48, 612-614
for 0.5 h at 10 "C and filtered under N2 The product, which is hygroscopic, was washed with ether (2 X 250 mL) and dried in a vacuum oven for 5 h at 40 "C. The yield of 2 was 101 g (97%); mp 149-150 "C. Anal. Calcd for C5H1J3rN706: C, 17.44; H, 2.91; Br, 23.24; N, 28.49. Found: C, 17.31; H, 3.08; Br, 23.13; N, 28.43. l-(Azidomethyl)-3,5,7-trinitro-1,3,5,7-tetrazacyclooctane (3). A solution of sodium azide (354 g, 5.45 mol) in water (1200 mL) was cooled to 5 "C, and with good stirring a solution of acetyl chloride (286 g, 3.64 mol) in methylene chloride (640 mL) was added in 2.5 h, maintaining the temperature at 5 "C with external cooling. The upper aqueous layer was siphoned off, and 2 (101
g, 0.294 mol) was added. The mixture was stirred for 3 h at 10-15 "C and filtered. The white solid was washed with methylene chloride (2 X 200 mL), water (200 mL), and ether (2 X 200 mL) and dried in a vacuum oven overnight at 40 "C. The yield of 3 was 71 g (79%): mp 130-131 "C; IR (KBr) 2080 (N3),1540 cm-l (N-N02). HPLC analysis showed a single peak. Anal. Calcd for C5HloNlo06:C, 19.61; H, 3.27; N, 45.75. Found: C, 19.99; H, 3.28, N, 44.99.
Registry No. 1, 5754-75-6; 2, 84454-93-3; 3, 84454-92-2; CH3CON3,24156-53-4; CH3COBr, 506-96-7.
Communications Electrophilic Substitution with Allylic Rearrangement (SE').Anti Stereoselectivity in Trifluoroacetolysis of Some Cyclohex-2-enylsilanes, -germanes, and -8tannanes
stereochemicalpreference is a valid matter for enquiry and is of synthetic importance, particularly for carbon electrophiles.8 Regrettably the information available has been derived from structurally diverse, atypical systems, involving some unusual ele~trophiles.~Despite the criticism that it has an inbuilt conformational bias,1° the cyclohex-2-enyl system is widely abundant and has provided considerable mechanistic inf0rmation.l' In this paper we report that trifluoroacetolysis of various cyclohex-2-enyl metallics displays a pronounced anti stereoselectivity. The cyclohex-2-enylmetallics 1-111 resulted from stan-
Summary: Trifluoroacetolysis of various cyclohex-2enylsilanes, -germanes, and -stannaries is demonstrated to be y regiospecific and highly anti stereoselective, as predicted for a dominating LUMO-HOMO interaction in a concerted SE2' process.
Sir: Regiospecific y cleavage by electrophiles is the most characteristic reaction of main-group a-allyl metallics and renders allylsilanes, -stannaries, etc. very useful allylation reagents (eq 1).Ir2 These demetalations display the I D m CH3CHZCHCHz-m
t
t E
-
CH3CHCrl=CHz
(1)
I, m = Si(CH,),, 11, m = Ge(CH,),, Ge(CH,),, SNCH,), Sn(CH,),
E
characteristics of SE2' (or SEi') proce~ses,~ the stereoelectronic aspects of which have been considered the~retically.~ Anti alignment of the approaching electrophile and the leaving group is the (qualitative) theoretical prediction for a fully concerted sE2' process? a result understandable in FMO terms (below) for the LUMO(E+)-HOMO interacti~n.~,~
"anti "
"distorted" HOMO5" of o-allyl metallic
Although the degree of concertedness in these substitutions may be unresolved,' the question of any intrinsic (1)See, for example: Fleming, I. Chem. SOC. Reu. 1981,10,83. (2)Negishi, E.I. "Organometallics in Organic Synthesis"; Wiley: New York, 1980;Vol. 1. Pereyre, M.; Pommier, J. C. J. Organomet. Chem. Libr. 1976,I, 161. (3)For a review see: Mangravite, J. A. Organomet. Chem. Reu. 1979, 7,45. (4) Anh. N. T. Chem. Commun. 1968,1089. Fukui, K.; Fujimoto, H. Bull. Chem. SOC. Jpn. 1967,40, 2018;1966,39,2116. Miller, S. I. Adu. Phys. Org. Chem. 1968,6,185. Gilchrist, T.L.; Storr, R. C. "Organic Reactions and Orbital Symmetry"; Cambridge University Press: London, 1972. ( 5 ) Liotta, C. Tetrahedron Lett. 1975,523. 1981,46, 1703. (6)Burgess, E. M.; Liotta, C. L. J. Am. Chem. SOC.
0022-3263/83/1948-0612$01.50/0
m
111, m = Ge(CH,),
nylation, germylation, and silylation of the appropriate cyclohex-2-enyl chlorides and have been fully characterized.12 Isomeric mixtures were obtained, but by manipulation of the precursor, "lopsided" cis/trans mixtures could be obtained. Trifluoroacetolysis (CF3COOD in CHC13, CH2C12,or dioxane) proceeded with complete allylic rearrangement in each system.13 In (symmetrical) I, stereochemical conclusions were based on 2H and 13CNMR examination (7) For kinetic information on protodemetalations of allylic systems see: Verdone, J. A.; Mangravite, J. A.; Scarpa, N. M.; Kuivila, H. G. J. Am. Chem. SOC.1975,97,843.Mangravite, J. A.; Verdone, J. A.; Kuivila, H. G. J. Organomet. Chem. 1976,104,303. Although a fully concerted mechanism would exhibit stereospecificity, second-order kinetics does not distinguish between such a mechanism and others involving the slow or reversible formation of an intermediate. See also: Fleming, I.; Langley, J. A. J. Chem. Soc., Perkin Trans. 1 1981,1421.Fleming, I.; Marchi, D.; Patel, S. K. J . Chem. Soc., Perkin Trans. 1 1981,2518. (8)The stereochemical aspects of these substitutions will be reported later. (9)For example see: Au-Yeung, B. W.; Fleming, I. J. Chem. SOC., Chem. Commun. 1977,79. Carter, M. J.; Fleming, I. Ibid. 1978,679. Overton, K. H. Chem. SOC. Reu. 1979,8 (4), 447. de la Mare, P. B. D.; Wilson, R. D. J. Chem. Soc., Perkin Trans 2 1977, 157. Wetter, H.; Scherer, P.; Schneizer, W. Helu. Chim. Acta 1979,62,1985. Kashin, A. N.; Bakunin, V. N.; Khutoryanskii, V. A.; Beletskaya, I. P.; Reutov, 0. A. J . Organomet. Chem. 1979,171,309. (10)For a review see: Magid, R. M. Tetrahedron 1980,36, 1910. (11)For example see: Goering, H. L.; Kantner, S. S. J. 0%. Chem. 1981,46, 2149 and previous papers by the former author. (12)Wickham, G.; Young, D.; Kitching, W. J. Org. Chem. 1982,47, 4884. (13)Protonolysis of deuterated analogues of 1 [m = Ge(CH&, Sn(CH& established complete allylic rearrangements.
0 1983 American Chemical Society
