J . Org. Chem., Vol. 58, No. 20, 1975 3633
NOTES No Diels-Alder adduct was found with anthracene or 1,4-diphenylbutadiene1 and no ene adduct was observed with 2,3-dimethyl-2-butene. As expected, it was found that IIIb could be hydrolyzed by base under mild conditions. For example, reaction of I I I b in the presence of air with 0.1 N lithium hydroxide in materdiglyme for 2 hr a t 25" gave cyclohexadiene and nitrogen. The adduct I I I b could be reduced to the dihydro derivative I V by hydrogen with 5% palladiumon-carbon catalyst in ethyl acetate a t 1 atm. Hydrolysis of this compound under conditions described above gave 2,3-diaza [2.2.2]bicycloo~t-2-ene,~ Treatment of I I I b with methanolic potassium carbonate gave V.
0 IV
I n conclusion, 1,3,4-thiadiazoline-2,5-dione can be used to form Diels-Alder adducts with moderately reactive dienes. The resulting adducts can readily be converted to hydrazine derivatives under mild conditions.' Experimental Section
4.8 (1 H , m, CH), 4.34 and 4.20 (2 H , 2 m, CHZ), and 1.38 (3 H, d, J = 6.5 Hz, CH3); mol wt (calcd for C7HsN2O2S, 184.0307) 184.0311. Preparation of 2-Carbomethoxy-2,3-diazabicyclooct-5-ene(V). -To a solution of 50 mg of anhydrous potassium carbonate in 1 ml of methanol was added 26 mg of IIIb. After stirring for 1.5 hr the solution was acidified with 10% hydrochloric acid and then made basic with potassium hydroxide. The solution was extracted with 4 x 10 ml of methylene chloride which was dried over sodium sulfate and evaporated to give 21 mg (95%) of colorless oil which was pure by tlc: ir (neat) 2.90, 3.11, 5.90, and 8.91 p ; nmr (CDC13) 6 6.53 (2 H , d of d, J = 3.6, 3.5 Hz, CH=), 4.80 (1 H , br, CH), 3.85 (1 H , br, CH), 3.73 (3 H , s, CH3), 3.50 (1 H, br, NH), and 1.3-2.3 (4 H , m, C H ~ C H Z ) . Reduction of Adduct 1IIb.-IIIb (196 mg) was dissolved in 5 ml of ethyl acetate containing 200 mg of 5% palladium on carbon, and the solution was stirred under hydrogen. After 4 hr the solution was filtered and evaporated, giving 190 mg (9570) of crystalline product (IV). Recrystallization from cyclohexane gave pure product: mp 129-131'; ir (CHCls) 5.85 and 6.05 p ; nmr (CDCla) 6 4.68 (2 H , br, CH) and 2.02 (8 H , br, CHz). 2,3-Diaza[2.2.;!]bicyclooct-2-ene.-To a solution of 50 mg of lithium hydroxide in 40 ml of 1:2 tetrahydrofuran-water was added 110 nig of Is'. After stirring for 6 hr under air, the solution was exhaustively extracted with dichloromethane which was dried and evaporated to give 49 mg (81%) of 2,3-diaza[2.2.2]bicyclooct-2-ene. Recrystallization from pentane-ether at -35' gave solid product: mp 136-138' (lit. mp 142");o nmr (CDCl3) 6 5.13 (f! H , br, CH) and 1.1-1.8 (8 H , br, CHZ); ir and uv data were as described.6 Hydrolysis of 1iIIb.-To a solution of 49 mg of IIIb in 3 ml of diglyme was added 3 ml of 0.2 M lithium hydroxide solution. After stirring for 2 hr at 25', gc analysis (10 ft, 10% TCEP, 30') indicated that cyclohexadiene had been formed. In a similar experiment using cyclohexane as an internal standard, gc analysis indicated that cyclohexadiene was formed in 9593 yield.
All Diels-Alder adducts were prepared by identical procedures. The reaction with cyclopentadiene is given as an example. Molecular weight measurements were by mass spectrometer. Preparation of Adduct 1IIa.-1 ,3,4-Thiadiazolidine-2,5-dione6 (1.18 g, 10 mmol) was dissolved in 20 ml of dimethylformamide, Registry No.-I, 41316-13-6; 11,41316-14-7; IIIa, 41316-15-8; 30 ml of tetrahydrofuran, and 0.5 ml of acetic acid. CycloIIIb, 41316-16-9 ; IIIc, 41316-17-0; IIId, 41316-18-1; IIIe, pentadiene (1.92 g, 30 mmol) was added, and the solution was 41316-19-2; IV, 41316-20-5; V, 41316-21-6; 2,3-diaza[2.2.2]cooled to -78". Lead tetraacetate (7 g, 15 mmol) was added, bicyclooct-2-ene, 3310-62-1. and the solution was stirred for 4 hr at -78". Then 1 ml of ethylene glycol was added, and the solution was allowed to warm to 25'. I t was then poured into 100 ml of water, which was extracted with 4 X 50 ml of methylene chloride. The methylene Carbonyliation of Saturated Hydrocarbons chloride was extracted with saturated sodium bicarbonate solution, dried over magnesium sulfate, and evaporated to give a Catalyzed by Copper(1) Carbonyl brown oil. Drying in vacuo (0.1 mm) for 18hr gave 1.75 g (96%) of crystals. The product was recrystallized from benzene-cycloYCISHIE SOUMA* A N D HIROSHI Sax0 hexane: mp 83.5-84.5"; ir (CHCl,) 5.80 and 6.00 p ; nnir (CDCla) 6 6.58 (2 H , d of d, J = 2, 2 Hz, CH=), 5.20 (2 H , m, CH), 2.38 (1 H , t of d, J = 9, 1.6 Hz, CHH), and 2.07 il H . Government Iiidustrial Research Institute, Osaka, t of d, J = 9, 1.8 Hz, CHH); mol wt (calcd for C~HJSZOZS, M.l'dorigaoka-1, Iksda, Osaka, Japan 182.0150) 182.0183. Preparation of Adduct 1IIb.-Adduct IIIb was similarly preReceived March 19, 1973 pared in 92% yield from 1,3-cyclohexadiene. The product was recrystallized from benzene-cyclohexane: mp 139.5-140'; ir (CHC13) 3.40, 5.84, 6.02 p ; nmr (CDC13) 6 6,60 (2 H , d of d, Several studies of reactions catalyzed by copper(1) J = 1.8, 2.4 Hz, CH=), 5.18 (2 H , m, CH), and 1.5-2.4 (4 H , carbonyl have been reported. Olefins react with carm, CHZ); mol wt (calcd for CsH31\J2O2S, 196.0307) 196.0307. bon monoxide a t room temperature and atmospheric Preparation of Adduct 1IIc.-Adduct IIIc was similarly prepressure with the catalysis of copper(1) carbonyl, and pared in 35% yield from isoprene. The product was recrystaltert-carboxylic acids were obtained in high yield.' lized from ether-petroleum ether (bp 30-60") at -78": mp 99100'; ir (neat) 5.80,6.00 p ; nmr (CDC13)6 5.65 (2 H , m, CH=), Similarly tert-carboxylic acids were prepared from the 4.25 (4 H , m, CHZ),and 1.92 (3 H , s, CHa); mol wt (calcd for carbonylation of alcohol x i t h the catalysis of copper(1) C?HsNzOzS, 184.0307) 184.0311. carbonyl.2 The pathway for formation of copper(1) Preparation of Adduct 1IIe.-Adduct IIIe was similarly precarbonyl has been described.lZ2 Haff and Koch have pared in 50% yield from 2,3-dimethylbutadienee The product was recrystallized from benzene-cyclohexane: mp 153.5found the synthesis of tert-carboxylic acid from paraffin 154.4'; ir (CHC13) 5.80 and 6.00 p ; nmr (CDCl3) 6 4.10 (s, 4 H , via hydride transfer using formic acid.3 Other studies CHz), and 1.75 (6 H, s , CHs); mol wt (calcd for C~HIONZO~S,were performed using different acid catalysts. Fried198.0463) 198.0460. mann4 reported the hydrogen fluoride catalyzed reacPreparation of Adduct I1Id.-Adduct IIId was similarly pretions of hydrocarbons and carbon monoxide a t elevated pared in 55% yield from trans-piperylene. The product was recrystallized from ether-pentane at -78": mp 65-66"; ir (1) Y. Souma, H . Sano, and J. Iyoda, J . Org. Chem., 38,2016 (1973). (neat) 5.78 and 6.00 p ; nmr (CDC1, 6 5.89 (2 H , m, CH=), (6) S.G. Cohen and R. Zand, J . Amer. Chem. Soc., 84, 586 (1962). (7) This work was assisted financially by the Kational Institutes of Health and the National Science Foundation.
(2) Y. Souma and H. Sano, Bull. Chem. SOC.J a p , in press: Y. Souma and H. Sano, K O Q ~Kagaku O Zosshi, 1 3 , 2723 (1970). (3) W. Haff and H. Koch, Justus Lzebigs Ann. Chem., 638, 122 (1960). (4) B. 9. Friedman and S.M. Cotton, J . Ore. Chem., a?', 481 (1962).
3634 J . Org. Chem., Vol. 38,No. 20, i97S
NOTES
TABLE I t&-CARBOXYLIC ACIDFROM SATURATED HYDROCARBON BY COPPER(1) C.4RBONYL C.lTALYSTa Saturated oompd
Olefin or alcohol
Methylcyclohexane (108-87-2)
Products
Yield, %
1-Hexene (592-41-6)
Methylcyclohexanecarboxylic acid (1123-25-7), 5.5b t-C7 acids. 1,P 2-Methylpentane (107-83-5) 1-Octene (11.1-66-0) 2,2-Dimethylpentanoic acid (1185-39-3) 40 2-Methyl-Zethylbutanoic acid (19889-37-3), 20 t-Cg acidsd 30 Z-Methylbutane (78-78-4) 1-Octene 2,ZDimethylbutanoic acid (595-37-9), 30 t-CO acidsd 60 2,2-Dimethylpropionic acid (75-98-9) 5 Met hylcyclopentane (96-37-7) 1-Octene Methylcyclopentanecarboxylic acid (5217-0540), 55 t-Cs acidsd 26 Methylcyclohexane 1-Hexene NIethylcyclohexanecarboxylic acid, 51 t-C7 acidsc 30 Methylcyclohexane 1-Octene Methylcyclohexanecarboxylic acid, 65 t-Cg acidsd 30 Methylcyclohexane 2-Propanol (67-63-0) Methylcyclohexanecarboxylic acid 20 2-Methylpropionic acid (79-31-2) 5 Methyl cyclohexane tert-Butyl alcohol (75-65-0) Rlethylcyclohexanecarboxylicacid, 33 2,2-dimethylpropionic acid 10 I-Hexanol (111-27-3) Methylcyclohexane R.lethylcyclohexanecarboxylic acid, 43 t-C? acidse 29 1-Octanol (111-87-5) Methylcyclohexane Methylcyclohexanecarboxylic acid, 70 t-Cs acidsd 10 1,4-Dimethylcyclohexane (589-90-2) 1-Ilexene 1,4-Dimethylcyclohexanecarboxylic acid [cis 55 (24097-71-0) to trans (24097-70-9), 1: I] t-C7 acidc 26 Octane (111-65-9) 1-Hexene t-Co acidsd 0 t-C7 acidsc 64 1-Hexene 2,2,4-Trimethylpentane (540-84-1 ) t-Cg acidsd 1 t-C7 acidsc 85 Cyclohexane (110-82-7) 1-Hexene t-C7 acids. 80 a In most cases, 0.2 mol of saturated hydrocarbon, 0.2 mol of olefin or alcohol, 0.02 mol of CuzO, and 105 ml of 98% H2SO4 were used. The reaction tempeiature was -30", and the reaction time varied from 1 to 2 hr. The pressure of carbon monoxide was 1atm. The alkenes and alcohols in the reaction mixtures yield tert-carboxylic acids too. Registry numbers are given in parentheses. Copper(1) compound was not used. c The ratio of 2,2-dimethylpentanoic acid t o 2-methyl-2-ethylbutanoic acid was 2: 1. The ratio of 2,2dimethylheptanoic acid (14250-73-8) to 2-methyl-2-ethylhexanoic acid (1185-29-1) to 2-methyl-2-propylpentanoic acid (31113-66-1) was4:Z:l.
pressures. Matsubara6 reported the carboxylic acid synthesis from paraffins in BFs H20 a t 20 a t m of carbon monoxide pressure. I n this paper, n-e describe the carbonylation of saturated hydrocarbons using copper(1) carbonyl catalyst in concentrated H2SO4 a t room temperature and atmospheric pressure. A hydride transfer mechanism can account for this reaction.
-
R,+
R:
+
Co
- -
+
R2H
CU(CO),+
R,H
+
R:
HZO
R,CO+
X,COOH
R, = general alkyl (n-,s e c - , t e r t - )
Results and Discussion Copper(1) carbonyl catalyst was prepared from copper(1) compounds and carbon monoxide in concentrated H2S04. Alcohols or olefins were used as the sources of alkyl cations. As soon as the mixtures of ( 5 ) M. Matsubara, M. Goto, K. Aomura, and H. Ohtsuka, Kogyo Kagaku Zasshz, 78, 1290 (1969); M. Matsubara, M. Goto, K. Aomura, and €1. Ohtsuka, ibid., 71, 1999 (1969).
saturated hydrocarbon and alkyl cation source were dropped into the copper(1) carbonyl suspension, carbon monoxide was absorbed and reacted immediately. The results of the carbonylation of saturated hydrocarbons using copper(1) carbonyl catalyst are shown in Table I. The yield of carboxylic acid was 7% in the absence of copper(1) compounds. Alcohol or olefin gives carbonium ion in concentrated H2SO4. This cation abstracts hydride ion from saturated hydrocarbon. Then a new alkyl cation is formed from saturated hydrocarbon and reacted with carbon monoxide. Only the saturated hydrocarbons which contain t-H atom undergo hydride ion abstract. Octane or cyclohexane does not react with carbon monoxide. I n Koch reaction, the products were obtained even for unbranched paraffin^.^ When the copper(1) carbonyl catalyst is used, the rate of carbonylation is very rapid. I n the mixture of unbranched paraffin and olefin, the rate of carbonylation of olefins is more rapid than that of hydride abstract ion from unbranched paraffins. Carbonylation of 2,2,4-trimethylpentane does not occur, although it has t-H atom in the molecule (owing to steric hindrance of neopentyl group). I n the comparison of alkyl cation sources, better results were obtained in longer chain alcohols (or olefins). The influence of H,S04 concentration on hydride transfer was examined in the reaction of methylcyclohexane and carbon monoxide in the presence of 1-
J . Ory. Chem., Vol. 38, No. 20, 1973 3635
NOTES loo
r------
100
80
80
60
,P
60
0 .%!
40
h
40
20
20
05
90
95
H2S04
10
100
temp.
Wt%
Figure 1.-The influence of HnS04 concentration, with CUZO (0.02 mol), methylcyclohexane (0.2 mol), and hexene (0.2 mol) at 30' (2,2-dimethylpentanoic acid to 2-methyl-2-ethylbutanoic acid, 2 : 1).
hexene. The results are shown in Figure 1. The ratio of the product 1 via hydride transfer increased cu(co)3+ H,SO,
mC", + 'L-'
t - C - acids
'COOH 1(I)
I1
with the increase of Hi304 concentration. At the Hi304 concentration of
