6813
drastic change of mechanism on going from DMSO to H,O as solvent. Experimental Section
( 5 ml of HzO/lOOml of solution) containing 9.1 X 10-3 M HCl and - 10-2 mCi of tritium was maintained at 25" for 4.5 hr. The reac-
tion mixture was added to 0.8 g of 4phenylsemicarbazide and allowed to stand at 25" for 1 hr. Dilution with 200 ml of HzO and chilling induced crystallization. The white needles were filtered and recrystallized from aqueous methanol (mp 147.5-148.5", l k 2 t z 5 mp 151-152"). Before addition of the substrate a small portion of the aqueous DMSO had been set aside for later counting. The semicarbazone products and the aqueous DMSO were analyzed for tritiwn26 The correction for the incorporation of tritium by the acetaldehyde by exchange is given in eq 11. The subscripts
Materials. Ethyl vinyl ether and dimethyl sulfoxide were obtained commercially and were purified by distillation. The latter was stored under dry nitrogen after distillation at 0.2 mm from calcium hydride. Standard hydrochloric acid and sodium hydroxide solutions were prepared in the usual ~nanner.~aDeuterium chloride was prepared from benzoyl chloride and D 2 0 . z 4The acidified aqueous dimethyl sulfoxide solutions were prepared gravimetrically. Each reaction mixture was titrated potentiometrically for acid after the completion of measurements. Isotopic Product Studies. Each product collection with ethyl vinyl ether as a substrate was accompanied by one in which acetaldehyde itself was used as substrate under otherwise identical conditions. In a typical experiment a solution of 0.6 ml of ethyl vinyl ether (or 0.35 ml of acetaldehyde) in 40 ml of aqueous DMSO
a and e refer to acetaldehyde and vinyl ether experiments, respectively. The counting rate due to exchange is r . (This is the total counting rate in the case of ra.) The incubation period is t , and n is the number of moles of derivative counted.
(23) 1. M. Kolthoff and E. B. Sandell, "Textbook of Qualitative Inorganic Analysis," The MacMillan Co., New York, N. Y., 1943. (24) H. C. Brown and C. Groot, J . A m . Chem. Soc., 64, 2223 (1942).
(25) P. P. T. Sah and T. S. Ma, J. Chinese Chem. SOC.,2, 34 (1934). (26) A. R. Friedman and E. Leete, J . A m . Chem. SOC.,85, 2141 (1963).
Anomalous Reactions of Bis ( trifluoromethyl ) diazomethane and Bis ( trifluoromethyl) diazirine with Saturated Hydrocarbons' William J. Middleton, David M. Gale, and Carl G. Krespan Contribution No. 1470 f r o m the Central Research Department, E. I. du Pont de Nemours and Company, Experimental Station, Wilmington, Delaware 19898. Received July 5 , 1968 Abstract: Bis(trifluoromethy1)diazomethane (1) reacted anomalously with cyclohexane to give a hydrazone (4) and an azo compound (3) as the major products in addition t o the expected carbene insertion product (2). Evidence for a radical chain mechanism is presented. Bis(trifluoromethy1)diazirine (8) also reacted abnormally with cyclohexane, but the major product was an unexpected imine (9) rather than the adducts obtained with bis(trifl4oromethyl)diazomethane. Hexafluoroacetone azine (14) gave the normal insertion product (2) with cyclohexane. Reactions with other hydrocarbons are discussed in light of possible mechanisms.
he thermal reactions of aliphatic and aromatic diazo compounds with saturated hydrocarbons have been intensively investigated. Such reactions normally give carbene insertion products and are frequently used to help establish the reactivity of the intermediate carbene. In no case have other primary products derived from the diazo compound and the saturated h y d r o c a r b o n been reported. This also appears to be true of the reactions of diazirines (cyclic diazo compounds) with saturated hydrocarbons, although these compounds have been less thoroughly
T
small amount of the expected carbene insertion product, [2,2,2-trifluoro-1-(trifluoromethyl)ethyl]cyclohexane (2), was obtained. The major products were an azo comp o u n d (3) and a hydrazone (4) (95 % combined yield of 2, 3, and 4). These a d d i t i o n products of the diazo compound 1 with cyclohexane were obtained even though the reaction was run at a temperature shown to be sufficiently high to generate a carbene, from l . 4
investigated.
We have found that unexpected reactions occur when either bis(trifluoromethy1)diazomethane (l)* or its cyclic isomer, bis(trifluoromethy1)diazirine (8)4 is heated with a saturated hydrocarbon. Bis(trifluoromethy1)diazomethane (1). W h e n 1 was heated at 150" for 8 hr in excess cyclohexane, only a ( 1 ) A portion of this work was communicated earlier [D. M. Gale, W . J. Middleton, and C. G. Krespan, J . Am. Chem. SOC.,87,657 (1965)l. (2) I. Hine, "Divalent Carbon," The Ronald Press, New York, N. Y., 1964. (3) E. Schmitz, Angew. Chem. Intern. Ed. Engl., 3,333 (1964). (4) D . M. Gale, W. J. Middleton, and C. G . Krespan, J . A m . Chem. SOC.88,3617 (1966).
CF3 2
(
+ (
)-N=N-$-H
I
I
hi-
A.-r
I
CF3 3
I
CF3 4
The structures of the products suggested that a d d u c t s 3 a n d 4 were f o r m e d from a common intermediate by the radical chain mechanism given by reactions 1-3. Additional experiments were c o n d u c t e d to test this Middleton, Gale, Krespan
Bis(tri)¶uoromethyl)diazomethane
6814 C6H12
+ R . +CeHii. + R H
(1)
+ (CF&CNz +CijHll-N=N-C(CF&
CBHll-
Table JI. Reaction of Bis(trifluoromethy1)diazirine
(10 g) and Cyclohexane
5
CeHiiN=N-C(CF& 5
+ C6Hii
5
(2)
+ CsHii.
3 or 4
Table I.
Reaction Products from Bis(trifluoromethy1)diazomethane and Cyclohexane
60 90 135 150 150 200 HO
16 16 16 6 8 8 8
-Composition, 2 3 4
Catalyst Nz[C(CH3)2CN]2 Benzoyl peroxidea r-Butyl peroxide None None None Hydroquinone
--No 6 6 8 12 10 61
%-b
reaction--44 39 12 59 33 2 60 30 2 52 36 9575) except for nitrogen was collected and shown to be 2 by direct infrared comparison with an authentic sample. Reaction of Bis(trifluoromethy1)diazomethane with Adamantane. A 25-g sample of the diazo compound, 180 ml of 1,1,2-trichloro1,2,24rifluoroethane, and 100 mg of t-butyl peroxide were heated together at 135" for 16 hr. The reaction mixture was distilled to give a mixture of products (28 g, 56%), bp 64-95" (2-0.8 mm). The fraction boiling at 64" (2 mm) was rich in the isomer shown t o be the azo compound 6. Purification by preparative gas chromatography (fluorosilicone column) gave 6 as a colorless liquid: n Z 5 ~ 1.4198; I9F nmr (neat) 6 73.3 (d, J = 7 Hz); H1nmr (neat) 6 73.3 (d, J = 7 Hz); H 1 nmr (neat) T 5.75 (septet, J = 7 Hz, C(CF&H), 7.8 (m, 3 bridgehead H), 8.2 (m, 12-methylene H); mass spectrum (70 eV) m/e 314 (parent), 135 (adamantyl carbonium ion). Anal. Calcd for C~~HIF,F~NZ: C, 49.68; H, 5.14; F, 36.27; N, 8.91. Found: C, 50.17; H , 5.33; F, 36.02; N,9.19. The higher boiling fractions, mainly at 83" (2 mm), solidified when cooled with a seed (obtained by preparative gc), and the hydrazone 7 was isolated by recrystallization from ethanol-water to give colorless crystals: mp 38-40'; IgF nmr (CC13F) 6 64.6 (A3B3pattern); H 1 nmr (CC13F) T 4.3 (s, NH), 5.6 (m, -CH, 3 H) 6.1 (m, CH2-C-N, 6 H), 6.5 (m, CH2-C-C); ir (KBr) 3345 (NH), 1595 cm-l (C=N); mass spectrum (70 eV) m/e 314 (parent), 135 (adamantyl carbonium ion). Anal. Calcd for C13H1~F6N2: C, 49.68; H, 5.14; F, 36.27; N, 8.91. Found: C,49.01; H, 5.26; F, 35.66; N, 8.72. Reaction of Bis(trifluoromethy1)diazirine (8) with Cyclohexane. In a typical run, 10.0 g of the diazirine, 25 ml of cyclohexane, and 50 ml of 1,1,2-trichloro-l,2,2-trifluoroethane (solvent) were heated in a 240-ml autoclave at 165" for 12 hr. The IQFnmr spectrum of the crude reaction mixture indicated that two major (69 and 30.5%) and one minor (0.5 %) fluorine-containing products were present. (Table I1 gives the product composition under various conditions.) Distillation gave 8.05 g of colorless liquid, bp 132-139". The two major products were separated by preparative glpc (fluorosilicone column). The 69% component was eluted first and identified as N-cyclohexylhexafluoroisopropylidenimine (9): bp 135"; 1QF nmr (25", neat) 6 64.2 (quartet, JFF = 7.5 Hz to d, JFR= 2.2 Hz), 71.2 (quartet, JFF = 7.5 Hz); lQFnmr (150", neat) 6 67.8 (s); H1 nmr (neat) T 6.0 (m, CH-N), 8.3 (m, 10 H). Anal. Calcd for CSHllF6N: C, 43.73; H, 4.48; F, 46.12; N, 5.67. Found: C,43.92; H,4.51; F,45.78; N, 5.79. The 30.5 Z component was eluted second and identified as (2,2,2trifluoro-1-trifluoromethy1)cyclohexane(2) by comparison of its ir and nmr spectra with those of an authentic sample. The 0.5% component was identified as compound 3 by comparison of its ir and nmr spectra with those of an authentic sample. Reaction of Bis(trifluoromethy1)diazirine with Neopentane. A mixture of 10.0 g (0.056 mol) of bis(trifluoromethy1)diazirine and
Middleton, Gale, Krespan
1 Bis(tri@oromethyl)diazomethane
6816 25 g of neopentane was heated at 165" for 12 hr in a 240-ml bomb. The bomb was cooled and vented, and the contents were distilled to give 5.7 g of a colorless liquid, bp 95-loOD,and 0.75 g of a black residue. Analysis of the residue indicated that it contained 5.25% N and 9.42% F. Gas chromatographic analysis on a silicone column of the distillate indicated two main components in the ratio 56:44. These components were separated on a preparative glpc column (fluorosilicone column). The principal component, having the longer retention time, was I,l,l-trifluoro-2-(trifluoromethyl)-4,4-dimethylpentane (15): bp 101-102"; nZ5D 1.3301; lgFnmr (neat) 6 6.83 (d, J = 8.4 Hz); H 1 nmr (neat) 7 9.05 (s, 3 CH3),8.29 ( d , J = 4.5 Hz, C-CHt-C), 7.18 (m, C(CF&H). Anal. Calcd for C8H12F6: C, 43.24; H, 5.45; F, 51.31. Found: C,43.41; H, 5.49; F,51.01. The other component, with the shorter retention time, was 2,2-dimethyl-N-[2,2,2-trifluoro1-(trifluoromethy1)ethylidenel-I-propylamine (16): bp 96-97"; t r Z 5 ~1.3303; lSF nmr (neat) 6 64.7 (quartet, J = 7.4 Hz to t, J = 2.7 Hz, 3 F) and 71.0 (quartet, J = 7.4 Hz to t, J = 2.0 Hz, 3 F); H 1 nmr (neat) 7 9.00 (s, 3 CH,) and 6.45 (m, C-CH2-N). Anal. Calcd for CsHl1FsN: C, 40.86; F, 48.46; N, 5.96; H,4.72. Found: C,40.99; F,48.58; N, 6.01; H,4.69. Reaction of Bis(trifluoromethy1)diazirine with Butane. A mixture of 15 g (0.084 mol) of bis(trifluoromethy1)diazirine and 40 g of nbutane was heated at 165" for 12 hr in a 4Wml stainless-steelbomb. The bomb was cooled and vented, and the contents were distilled to give 11.08 g of colorless liquid, bp 81-92". Gas chromatographic analysis and I g F nmr indicated four principal products present in the ratio 32:27:34:6 (by 19F nmr integration). Preparative glpc (fluorosiliconecolumn) gave the following compounds in order of retention time. l-Methyl-N-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]propylamine (17) was the original 3 2 z component: bp 82-83"; 19F nmr (neat) 63.4 ppm (quartet, JFF = 7.7 Hz to d, J FH = 2 Hz, 3 F) and 71.0 ppm (quartet, J = 7.7 Hz, 3 F). Anal. Calcd for C7HBFsN: C, 38.01; H , 4.10; F, 51.55; N, 6.34. Found: C,38.31; H,4.30; F, 51.72; N,6.43. 1,l ,l-Trifluoro-2-(trifluoromethyl)-3-methylpentane (19)was the original 27% component: bp 88-89"; lgFnmr (neat), two pentets (probably overlapping quartets with JFFand JFH= ca. 8.5 Hz) centered at 62.1 ppm.
Anal. Calcd for C7HlaF6: C, 40.39; H, 4.84; F, 54.77. Found: C,40.51; H,4.92; F, 55.00. 1,1,1-Trifluoro-2-(trifluoromethyl)hexane(20)was the original 34% component: bp 88-89"; l@Fnmr(neat) 67.9ppm(d,J = 8.1 Hz). Anal. Calcd for CvHloFs: C, 40.39; H, 4.84; F, 54.77. Found: C,40.47; H,4.90; F, 54.92. N - [2,2,2 - Trifluoro 1 - (trifluoromethyl)ethylidene]butylamine (18) was the original 6 % component: lgF nmr (neat) 64.6 ppm (quartet, JFF= 7.5 Hz t o t , JFH = 2.3 Hz, 3 F) and 71.1 ppm (quartet,JFF = 7.5 Hz to t, HFH= 1.6 Hz, 3 F). Anal. Calcd for C7HBF6N: C, 38.01; H, 4.10; F, 51.55; N, 6.34. Found: C,38.32; H,4.40; F,51.60; N,6.44. Reaction of Hexafluoroacetone Azine (14) with Cyclohexane. A mixture of 25 ml of cyclohexane and 10.0 g of hexafluoroacetone azine was heated at 165" for 12 hr in a 145-ml bomb. The bomb was cooled and vented. Gas chromatographic analysis indicated only one major peak in addition to cyclohexane. Distillation gave 5.64 g (40 of 2,2,2-trifluoro-l-(trifluoromethyl)ethylcyclohexane (2), bp 57-58" (25 mm), which was identified by comparison of its ir and nmr spectra with those of an authentic sample. N-Cyclohexyl-1,1,1,3,3,3-hexafluoro-2,2-propanediamine(10). Method 1. Hexafluoroacetone imine, 25 ml, was distilled into 19.8 g (0.182 mol) ofstirred cyclohexylamine over 45 min. Distillation at reduced pressure gave 35.1 g (70%)of the diamine 10 as a colorless ~ 19Fnmr(neat)6 80.2(s). liquid: bp 54-55"(4.4mm); 1 z Z 5 1.3903; Anal. Calcd for C9HlaF6N2: C, 40.91; H, 5.34; F, 43.15; N, 10.61. Found: C, 40.97; H , 5.16; F,43.35; N, 10.53. Method 2. A mixture of 5 g of ammonia and 25 g of a 50:50 mixture of compounds 9 and 2 (prepared from cyclohexane and 8) was heated at 100" in 8 hr in a 145-ml bomb. Distillation gave 6.77 g of 2, bp 135", and 6.70 g of the diamine 10, bp 62-63" (3.8 mm). Both products were identified by comparison of their ir spectra with those of authentic samples. Reaction of Bis(trifluoromethy1)diazirine with Benzene. A mixture of 50 ml of benzene and 10 g of bis(trifluoromethy1)diazirine was heated at 165" for 12 hr in a 240-ml stainless-steel bomb. The bomb was cooled and vented, and the contents were distilled to give 11.21 g (85z) of colorless liquid, bp 132-141 '. Gas chromatographic analysis indicated the product was composed of 85 7,7-bis(trifluoromethyl)-l,3,5-~ycloheptatriene~ and 15% [2,2,2trifluoro-1-(trifluoromethyl)ethyl]benzene.
-
z)
z
A New Synthesis of Olefins from Carbonyl Compounds and Phoshonic Acid Bis Amides E. J. Corey and George T. Kwiatkowski Contribution f r o m the Department of Chemistry, Harvard University, Cambridge, Massachusetts 02138. Received July 5 , 1968 Abstract: The reaction of a-lithio phosphonamide derivatives with aldehydes and ketones affords P-hydroxy phosphonamides by carbonyl addition in excellent yields. Thermal decomposition of these adducts in benzene or toluene solution a t reflux leads t o olefins by elimination of the elements of the corresponding phosphoric acid amide. &Hydroxy phosphonamides can also be synthesized by reduction of @-keto phosphonamides, which in turn are available by the reaction of a-lithio phosphonamides with carboxylic esters. Methods for the stereoselective synthesis of a number of cis and trans olefins are described. The phosphonamide route t o olefins is complementary t o the Wittig and Horner-Emmons-Wadsworth methods, having certain general advantages which are discussed herein.
T
he discovery that 0-hydroxy sulfinamides undergo thermal decomposition to olefins, amines, and sulfur dioxide (eq 1) suggested that the analogous trans-
A
RzC(oH)CH2SoNHR'
R2C=CHz +
+ R"H2
(I)
formation of O-hydroxy phosphonamides 3 to olefins
and phosphoric acid bis amides might also occur.
Journal of the American Chemical Society 1 90:24
AS
r e p o r t e d in a preliminary communication, 0-hydroxy phosphonamides 3 in fact do decompose readily in refluxing benzene to form olefins. This reaction, in conjunction with the carbonyl addition reaction illustrated (1) (a) E. J. Corey and T, Durst, J . A m . Chem. Soc., 88, 5656 (1966); (b) E. J. CoreY and T. Durst, {bid.,90,5548 (1968). (2) (a) E. J. Corey and G. T. Kwiatkowski, ibid., 88, 5652, 5653 (1966); (b) E. J. Corey, Pure ~ p p i Chem., . i4,i9 (1967).
November 20, 1968
