C A T A L Y T I C A L K Y L A T I O N OF T E T R A L I N

COMMUNICATION 8. ALKYLATION OF TETRALIN WITH ALKENES IN PRESENCE

OF ALUMINUM

N. I . S h u i k i n a n d N. A . P o z d n y a k

N. D. Zelinskii Insti tute of Organic Chemistry, Academy of Sciences, USSR Translated from Izvest iya A kademi i Nauk SSSR, Otdelenie Khimicheskikh Nauk, No. 8,

pp. 1455-1457, August, 1962 Original a r t i c le submitted February 12, 1962

Taking the a lkyla t ion of te t ral in with 1-nonene as our example [1], we showed that i t is possible to a lky la te the aromat ic nucleus with alkenes in presence of a luminum. Reaction went at 165 ~ under atmospheric pressure in presence of 0.124 mole of nonyl bromide per mole of tetral in. We later showed [2] that the a lkyla t ion of te t ral in with alkyl hal ides proceeds more readi ly in a nitrogen atmosphere. The most ac t ive of the alkyl halides that we took for invest igat ion was found to be heptyl bromide; at 65* i t reacted comple te ly with te t ra l in with formation of

heptyl te t ra l in .

In the present work we investigated the a lkyla t ion of te t ra l in with 1-heptene , 1-nonene, a mixture of nonenes, and 1-decene. The a lkyla t ion of te t ral in was carried out in a nitrogen atmosphere in presence of 0.09 mole of a lkyl

ha l ide per mole of te t ral in in an a lkane solution.

CnH

The possibi l i ty cannot be excluded that react ion proceeds with par t ic ipat ion of in te rmedia te ly formed a lky l -

a luminum bromides:

2A1 + 3AlkBr ~ AlkAIBr2 -k Alk~A1Br

We invest igated the effect of temperature , amount of a luminum taken, and the molar rat io of te t ra l in to a lkene on the yield of a lkyl te t ra l in . As a result of the experiments we succeeded in carrying out the a lkyla t ion at a lower temperature (up to 95 ~ and with a smal ler amount of a lkyl ha l ide (up to 0.09 mole per mole of te t ra l in , instead of 0.124 mole) than in the previous invest igat ion [1]. We also invest igated the effect of the di lut ion of the alkenes with alkanes on the completeness of the a lkyiat ion reaction. I t was shown in this work that the best results are obtained with the use of heptyl bromide as act ivator . In this case the yields of hep ty l - , nonyl - , and d e c y l - t e t r a - lins were 80.0%. 74.5%, and 56%, respect ively , on the amounts of alkenes taken for react ion.

E X P E R I M E N T A L 1-Alkenes were prepared bY the pyrolysis of the corresponding alkyl aceta tes [3], and the mixture of nonenes by

the dehydration of nonyl alcohol over a lumina at 350 ~ [4]. The a lkyla t ion of te t ra l in was carried out in a flask from which air had been displaced by the passage of nitrogen for 30 min; first, freshly prepared a luminum filings were in - troduced into the flask, and then, after a 15 rain heat ing in a nitrogen atmosphere at 70 ~ , a mixture of 5 ml of te t ra l in and 0.01 mole of a lkyl ha l ide was added; a vigorous react ion then set in with l ibera t ion of hydrohal ic acid. Then, at not above 95", a mixture of the remaining te tral in with 1-nonene and nonane was added with stirring. When the reac t ion was comple te , the liquid product was fil tered from the small resinous prec ip i ta te formed in the course of the react ion and Was fractionated through a column of 15 p la te eff ic iency. Alkenes and the nonane fraction were dis- t i l led off at a tmospheric pressure, and the alkyl tetral ins formed were vacuum-dis t i l l ed off at a residual pressure of

3-6 ram.

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TABLE i. Alkylation of Tetralin with Alkenes

i Amount of IMolar rati~ memp,, �9 . . . . [tetralin 1 ofexpt. ' ,S ~ l u m - n o n - i a l - i: alkene [ linum lane t(ene (~C)

_, ~ l_L(g) i(ml) I Cg)

IDuratio n Amt. ofmonoalRyl~Amt, of----'--di-

t !(%on a l - / l i n ob- [ofexpt., 'te~alin obtaine___~d talkyltetra-

i 2 3 4 5 6 7 8

0,08 -- 0,08 0,08 0,08 20 0,1351 30 0,t351 6o 0,135[ 70 0,1351 30

12,3" I t2,3 I t2,31 ~2,3[ t2,3 I t2,al t2,31 6 ,2[

9 10 t t t2 t3. t4 15

0,08 I o,o8 I o,08t 0,t351 30 0,t35[ 30 0,t35 60 0,i35 30

15,7 15,7 t5,7 15,7 t5,7 t5,7

7,9

t 6 1 0 , t 3 5 1 3 0 t 7 ' 9 I 1 7 0,t35/ 70 7,9 i8 0,1351 85 7,9

t9 20 21 22 23

0,08 ] -- 0,08 [ o,o81 2; 0,t351 0,1351

t7,5 ] 8 ,8 [

t7,51 17,5[ t7,51

Alkylation with 1-heptene t : I 1 t0 4 t : 1 65 4 t : t 65 4 I :1 65 4 1:1 95 2 I :1 95 4 l : t 95 4 2 : t 95 4

Alkylation with 1-nonene t : I t10 4 i : I i t0 7 I :1 l l0 4 t : t 95 4 l : ! 65 4 t : i '95 2: I 95 4

12,5 43,0 18,0 14,0 13,0 t4,5 t9,0 t2,0

t4,0 15,0 14,7 f7,0 6,0

47;1 12,0

Alkylation with nonene 2 :1 } 95 l 4 2: t 95 4 2: t 95 4

Alkylation with 1-decene t : 1 ] 110 8 2: t I 1t0 7 I : t i 65 8 i : t l 95 4 t : i I 95 4

mixture

9,0 8,0

9,0 8,t 3,3

19,t 19,5

41,5 45,2 63,t 49,1 45,2 50,0 68,0 80,0

43,5 46,5 45,6 52,7 18,7 52,7 74,5

74,5 56,0 50,0

26,5 47,0

9,7 56,0 57,5

12,1 8,0 5,2 8,t 6,3 7,0 6,2 5,0

8,5 8,0 3,t 9,2 2,t 918 2,5

2,5 3,0 2,5

6,5 4,0 2,5

t0,0 t0,5

*Experiments 1-8, 14-18, 22, and 23 were carried out in presence of heptyl bromide; Experiments 9-13 in presence of nonyl bromide~ and Experiments 19-21 In presence of deeyl bromide,

TABLE 2. Properties of Alkyltetralins and the Results of Their Spectrographic Investiga- tion

Bopo, "C I n2D o (p, ram) t I No. of I [No. of ' ;

Igroups

Proposed structural formula

i33--t34(3) 134-t43(a)

178--182(3) t83--t86(3)

t57--t63 (4)

210--215 (5} 2t5--2t8 (5)

1,5150 !,5i50

t,5060 t,5065

1,5105

i,5025 t,5020

Alkylati0n with 1-heptene

600 9,6 i46 555 9,0 2i0

825 12,0 402 t830 t2,0 400

Alkylation with l-nonene

690 ! i0,8 156 I

1005 I t5,0 376 1080 l ~6 397

t ,5 2

1,5

0

R -- ~-- (0h -- c

/ I% -- .IC -- (Oh -- Oh

C /

Ir --- C -- (Ch -- C

!r -- IC/-- (O), --C|~

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B.p., ~

(p, ram)

i 5 7 - - t 6 3 ( 4 )

2i5--220 (5)

i 9 0 - - 2 0 0 (6)

240--260 (6).

t 1

~<), o f

groups

f

�9 I N o . of %o ICIts

Igroups

Table 2 (Cont.)

Proposed structural

formula

i , 5 i lO

t,5050

t,5060

i ,5020

685

t095

764

t3 i0

Allcyladon with nonenemix tu re I

i0 ,g 170 I t , 7 I I

t6 4t0 I 4

Alkylat ion with 1 -deeene

i t , 7 200 2

19,8 395 4

c /

R - c - ( c ) , - C

c /

R -- lC -- (C), -- OI,

O

R -- C / - (O), - - O

C /

R - - [O/~ (C), - OI,

* s l = intensity of absorption band in region of 2930 cm -1.

* * s2 = intensity of absorption band in region of 2960 c m - 1

We studied the effects of temperature , duration of the exper iment , molar ratio of tetral in to a lkene, and amounts of a luminum and nonane on the yield of alkyl tetral ins . In each exper iment we took 16.5 g, or 0.125 mole , of te t ra l in and 0.01 mole of a lkyl hal ide . The amounts of a luminum, a lkene, and nonane taken are given in Tab le 1.

From the data in Table 1 i t wil l be seen that the opt imum conditions for the a lkyla t ion of te t ra l in with a l - kenes may be considered to be. temperature 95 ~ t ime 4 hr, and amount of a luminum 0.135 g, which corresponds to 0.04 g - a t o m per mole of tetral in. With a molar rat io of tetral in to a lkene of 2 : 1 the yield of monoalkyl tetral ins

attains 80 % on the a lkene taken.

For the comple te react ion of alkenes with tetral in i t is desirable to use a mixture containing 25-30% of a l - kenes (Experiments 8, 15, and 16). When a 10-13% mixture is used, about 30% of tile alkenes do not react (Ex-

per iments 17 and 18).

As a result of analysis with the aid of infrared spectra it was shown that the alkyl tetral ins that we obtained may be regarded as 6 -mono- and 6 ,7-d i - i soa lky l te t ra l ins (see "Fable 2).

The mixture of nonenes was made ava i l ab le to us by E. A. Timofeeva ; the infrared spectra were determined by I. N. Lifanova. The authors express their thanks to th'ese workers.

S U M M A R Y 1. I t was shown that te t ra l in can be a lkyla ted with alkenes in presence of 0.04 g -a tom of a luminum and 0.09

mole of a lkyl ha l ide per mole of tetral in.

2. At 95 ~ alkenes reac t to comple t ion with te t ral in with formation of up to 80% of monoalkyl te t ra l ins .

L I T E R A T U R E C I T E D 1. N . I . Shuikin and N. A. Pozdnyak, Izv. AN SSSR, Otd. Khim. , 1094 (1961).

2. N . I . Shuikin, N. A. Pozdnyak, and I. N. I.ifanova, Izv. AN SSSR, Otd. Khim. , 695 (1962). 3. I . P . Wibout and A. I. Vanpelt , Recueil , Tray. Chim. , 5_~7, 1055 (1938). 4. C . A . Walker , Industr. and Engng. Chem. , 4._}_1, 2640 (1949).

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