Selective Alkylation of Aniline With Methanol Over Boronsilicate Molecular Sieve

P.A. Jacobs ;mi R.A. van Santcn (Editors), Zeolifes: Fncts, Figires, Fittiire 0 1989 Elsevier Science Publishcrs B.V., Amsterdam - Printed in The Netherlands

I095

SELECTIVE ALKYLATION OF ANILINE WITH METHANOL OVER BORONSILICATE MOLECULARSIEVE

S.I.

WOO',

J.K. LEE1, S.B. HONG2 , Y.K. PARK 1 and Y.S. UH2

'Department o f Chemical Engineering, Korea Advanced I n s t i t u t e o f Science & Technology, P.O.Box 131, Cheongryang, Seoul , (Korea) 'Division o f Chemistry, Korea Advanced I n s t i t u t e o f Science & Technology, P.O. Box 131, Cheongryang, Seoul, (Korea)

ABSTRACT The s e l e c t i v e a l k y l a t i o n o f a n i l i n e w i t h methanol catalyzed by b o r o n s i l i c a t e s was investigated. C o r r e l a t i o n o f a c i d i t y o f ZSM-5, (B)ZSH-5 and ion-exchanged (B)ZSM-5's w i t h t h e s e l e c t i v i t y towards methylated anilines suggested t h a t strong a c i d s i t e s (Tm>600K), medium a c i d s i t e s (450
To1 u i d i ne(T) , N-methyl ani 1i n e ( NMA) and

N,N-dimethylani 1i n e ( NNDMA) are

major products i n t h e a l k y l a t i o n o f a n i l i n e w i t h methanol. They are

the

important

intermediate chemicals i n organic synthesis. Liquid-phase a l k y l a t i o n comnerciali z e d i n 1866 has been extensively used i n i n d u s t r y t o prepare these a l k y l a t e d a n i l i n e s ( r e f . 1). However, corrosion problems a r i s e due t o the use o f

strong

acid as a c a t a l y s t a t high temperatures and pressures. Generally, liquid-phase r e a c t i o n gave

a higher y i e l d than vapor-phase reaction; w h i l e t h e former l e d t o

many undesired by-products. The l a t t e r gave NMA ( r e f s . 2-3) o r NNDMA ( r e f . 4) as a major product. Vapor-phase methylation o f a n i l i n e w i t h z e o l i t e s NaX, NaY

and

ZSM-5 was reported i n recent years ( r e f s . 5-6). Previous studies i n d i c a t e d t h a t the major f a c t o r s i n f l u e n c i n g t h e a c t i v i t y and s e l e c t i v i t y o f vapor-phase a n i l i n e methylation are t h e acid-base p r o p e r t i e s and shape s e l e c t i v i t y

i n the

solid

c a t a l y s t . I n t h i s study, b o r o n s i l i c a t e s ((BIZSM-5) o f d i f f e r e n t Si02/B203 r a t i o were prepared and exchanged w i t h Mg, Cu, Zn i o n s t o modify t h e acid-base propert i e s and shape s e l e c t i v i t y from those o f p e n t a s i l ZSM-5. The c a t a l y t i c p r o p e r t i e s

o f these b o r o n s i l i c a t e s i n t h e a l k y l a t i o n r e a c t i o n o f a n i l i n e w i t h methanol were investigated. EXPERIMENTAL Synthesis o f boronsi 1i c a t e s ( B l z s M - 5 ' ~ o f d i f f e r e n t SiO2/62O3 r a t i o s were prepared by hydrothermal

1096 c r y s t a l l i z a t i o n a t 15OoC f o r 3 days from a m i x t u r e c o n t a i n i n g c o l l o i d a l s i l i c a , b o r i c acid, NaOH and TPABr according t o Howden's method ( r e f . 7 ) . D e t a i l e d i n f o r m a t i o n on t h e preparation o f (B)ZSM-5 i s shown i n Table 1. I o n exchange o f NH4(B)ZSM-5 Na(B)ZSM-5 was ion-exchanged t h r e e times w i t h 0.1 M NH4OH a t room temperature. This NH4(B)ZSM-5 was ion-exchanged t w i c e w i t h 0.1 M MgC12 a t

room temperature,

w i t h 0.1 M Cu(OAc12 and 0.1 M Zr1(N03)~ a t 8OoC f o r 12 hrs. These ion-exchanged (B)ZSM-5's were calcined a t 55OoC f o r 5 h r s t o produce H(B)ZSM-S's. Characterization,

r e a c t i o n and NH3 TPD

Elemental analyses were done by atomic absorption spectroscopy. XRD p a t t e r n s were obtained w i t h a Rigaku D/Max 11-A d i f f r a c t o m e t e r . I R spectra were recorded with

an

Analect 6160 FTIR. "B NMR

spectra were obtained

w i t h a Bruker AM-200

high r e s o l u t i o n NMR spectrometer operating a t a f i e l d of 4.7 T w i t h

a

standard

MAS probe. TGA analysis was performed w i t h a Ulvac Riko TPD-5000 thermogravimet r i c analyzer by r a i s i n g t h e temperature a t a r a t e o f 40°C/min. Vapor phase methylation o f a n i l i n e w i t h methanol was c a r r i e d o u t i n a d i f f e r e n t i a l t u b u l a r r e a c t o r . Products were analyzed w i t h GC using a 10% Carbowax 20M/ chromosorb W-HP( 80/100) column. For NH3 TPD, 0.29 o f sample was put i n a TPD r e a c t o r and purged w i t h He a t 4OO0C f o r 2 hrs. NH3 was adsorbed a t 25OC f o r 30 min, then purged w i t h

100 m l /

min f l o w o f He t o desorb physisorbed NH3 a t 25OC. NH3 TPD spectra were obtained by r a i s i n g t h e temperature o f TPD r e a c t o r a t a r a t e o f 10°C/min w i t h a temperat u r e programmable c o n t r o l l e r (RKC, REX-P100) i n t h e 60 ml/min f l o w o f He. TABLE 1 Detailed informations on t h e preparation o f (BIZSM-5. Sample

Composition o f r e a c t a n t mixture ( 9 ) Ludox

Boric a c i d

(B)ZSM-5 (60Ia 22.83 2.1 (B)ZSM-5 (250) 22.83 0.38 0.21 (B)ZSM-5 (450) 22.83 (B)ZSM-5 (650) 22.83 0.15 (B)ZSM-5(1300) 22.83 0.08 22.83 0 Silicalite aNumbers i n parentheses i n d i c a t e t h e B2O3 i n t h e f i n a l product. RESULTS AND DISCUSSION Characterization

TPABr

NaOH

6.2 6.2 6.2 6.2 6.2 6.2

1.22 1.22 1.22 1.22 1.22 1.22

H20

123 123 123 123 123 123 mole r a t i o o f SiO2/

1097

(i)=. (B)ZSM-5's(SiO2/6203 = 60, 250, 450, 650 and 1300) showed a ZSM-5 structure. The peaks between 19.5 and 31' (2e angle) suggested t h a t (6)ZSM-5 has e i t h e r orthorhombic or monoclinic symmetry depending on t h e preparation cond i t i o n and t h e Si02/62O3 r a t i o . The angles between t h e two peaks (45O<2ec46O) decreased and t h e widths o f each peak increased as t h e r a t i o o f SiO2/B2O3 decreased as shown i n Fig. 1, which was a l s o observed i n t h e XKD p a t t e r n s o f (A1)ZSM5 ( r e f . 8) and (FeIZSM-5 ( r e f . 9 ) . (ii)

g.Although t h e

I R bands o f (6)ZSM-5 are s h i f t e d a few wavenumbers from

those o f (A1)ZSM-5, (B)ZSM-5(60) c l e a r l y has t h e s t r u c t u r e o f ZSM-5 (see Fig. 2). The bands a t 1100, 450, 550, 790 and 1220 cm" are a t t r i b u t e d t o t h e i n t e r n a l T-0 streching v i b r a t i o n , T-0 bending v i b r a t i o n , v i b r a t i o n o f double f i v e rings, external symmetric T-0 stretching, and v i b r a t i o n o f five-membered rings, respect i v e l y . The band a t 908 cm-l confirms t h e presence o f B atoms i n t h e t e t r a h e d r a l s i t e s o f ZSM-5 ( r e f . 10). Not any s i g n i f i c a n t change i n I R spectrum o f (BIZSM-5 calcined a t 55OoC i s observed except f o r t h e s l i g h t decrease i n t h e i n t e n s i t y o f the band a t 908 cm-'. ( i i i ) "6 NMR. The MAS "6-NMR spectrum o f (B)ZSM-5(60) has a sharp

band a t

-3.5 ppm w i t h a small shoulder a t -1.5 ppm measured from t h e external reference materials, BF30Et.2 ( r e f . 11). Gabelica e t a l . reported t h a t boron atoms substi-

416

415

29 F i i . 1. XRD p a t t e r n s between 45O and 46 ( a ) S i O /B2O3=wy ( b ) S i O /B2O3 =1300, ( c ) $i02/6203=450, ( d f Si02/ 62O3=6O.

WAVENUMBER (cm-' ) Fig. 2. FTIR spectra o f (A1)ZSM-5 ( a ) and (B)ZSM-5(60).

1098

tuted t e t r a h e d r a l l y i n ZSM-5 g i v e a sharp band a t -3.5 ppm i n "6-NMR ( r e f . 121, i n d i c a t i n g t h a t our (B)ZSM-5ls have 6 atoms incorporated i n t o t h e t e t r a hedral s i t e s o f ZSM-5. ( i v ) TGA and SEM. TGA analyses o f (B)ZSM-5(60) and unsupported TPABr i n d i c a t ed t h a t t h e decomposition of TPA+ i o n s entrapped i n t h e cage o f (6)ZSM-5 s t a r t e d a t 45OoC and TPABr decomposed a t 3OO0C. The higher decomposition temperature o f TPA'

i o n s o f (6)ZSM-5 i s due t o t h e s t a b i l i z a t i o n by t h e a t t r a c t i o n i n t e r a c t i o n s

3

373 473 573 TEMPERATURE

613 a

*K

773

Fig. 4. NH3 TPD spectra o f ZSM-5 and (B)ZSM-5' S.

Fig. 3. SEM p i c t u r e o f (BIZSM-5 (SiO2/62O3=6O)

504 Si02/B203 = 250

w i t h oxygen anions i n ZSM-5.

(BIZSM-5

(60) c r y s t a l s are s p h e r i c a l l y shaped as

shown i n Fig. 3. The c r y s t a l shapes o f (B)ZSM-5ls became more spherical and t h e c r y s t a l s i z e decreased from 8 wn t o 3

urn upon decreasing t h e r a t i o o f Si02/

6203 from m t o 60. ( v ) NH? TPD. F i g . 4 shows NH3

TPD

spectra o f ZSM-5 and (6)ZSM-5 o f d i f -

1

273

I

1

I

I

373 473 573 673 TEMPERATURE a 'K

I

773

Fig..5. NH3 TPD spectra o f (B)ZSM-5 and ion-exchanged (l31ZSM-5'~.

f e r e n t SiO2/62O3 r a t i o s . (H)ZSM-5 ( S i / A1 = 90) has a strong a c i d s i t e (Tm> 650 K ) , which i s not present i n (6)ZSM5. The strength and t h e number o f a c i d s i t e s decreased as t h e mole r a t i o o f

1099

SiO2/6203 increased. The peak temperature o f NH3 TPD spectra decreased i n t h e order o f H(B)ZSM-~>M~(B)ZSM-~>Z~(B)ZSM-~>CU(B)ZSM-~ as shown i n Fig. 5 i n d i c a t i n g t h a t ion-exchange w i t h Mg2+, Zn2+ and Cu2+ decreased t h e strength o f

acid

s i t e s i n H(B)ZSM-5. A n i l i n e a l k y l a t i o n w i t h methanol A n i l i n e a l k y l a t i o n w i t h alcohols catalyzed over s i l i c a gel a t 300-400°C produced mainly N-alkylated a n i l i n e ( r e f . 13). H i l l e t al. reported t h a t metal oxides supported on alumina show t h e highest a c t i v i t y f o r N - a l k y l a t i o n r e a c t i o n w h i l e phosphoric acid, calcium sulfate, z i n c oxide and magnesium oxide produce C-alkylates s i g n i f i c a n t l y ( r e f . 14). Chen e t a l . reported t h a t modified ZSM-5 c a t a l y s t s have d i f f e r e n t c a t a l y t i c a c t i v i t i e s and s e l e c t i v i t i e s i n t h e methylat i o n r e a c t i o n o f a n i l i n e ( r e f . 6). The increase i n b a s i c i t y increased t h e a c t i v i t y and t h e s e l e c t i v i t y towards N-alkylates. Onaka e t al. reported t h a t Nb u t y l a t i o n o f a n i l i n e w i t h b u t y l i o d i d e r e q u i r e s both a c i d i c and basic s i t e s f o r s e l e c t i v e N-alkylation ( r e f , 2 ) . I n t h i s study, we i n v e s t i g a t e d t h e changes

in

c a t a l y t i c a c t i v i t y and s e l e c t i v i t y i n t h e a n i l i n e methylation r e a c t i o n a r i s i n g from t h e m o d i f i c a t i o n o f acid-base p r o p e r t i e s o f ZSM-5 by isomorphous s u b s t i t u t i o n o f A1 by 6 and t h e ion-exchange o f (6)ZSM-5 w i t h Cu2+, Zn2+, and Mg2+. ( i ) E f f e c t o f contact time. (B)ZSM-5(60) was used t o i n v e s t i g a t e t h e e f f e c t o f contact time on the a c t i v i t y and product d i s t r i b u t i o n (Fig. 6). Conversion increased l i n e a r l y w i t h contact time i n d i c a t i n g t h a t t h e r e are no external mass t r a n s f e r l i m i t a t i o n s . A s t h e contact t i m e increased, t h e s e l e c t i v i t y towards NMA decreased due t o t h e f u r t h e r methylation o f NMA t o NNDMA and NMT. The s e l e c t i v i t y towards NMT passes a maximum a t l/LHSV=.0.58 and a f u r t h e r decrease i n LHSV r e s u l t e d i n t h e formation o f NNDMT. The s e l e c t i v i t y towards NNDMA does not decrease suggesting t h a t NNOMT i s not produced by t h e methylation o f NNDMA, b u t produced from t h e methylation o f NMT. ( i i ) E f f e c t o f temperature. The a c t i v i t y o f (B)ZSM-5(60) showed a maximum a t 4OO0C and decreased above 4OO0C, which i s assumed t o be due t o d e a c t i v a t i o n caused by formation o f coke (Fig. 7 ) . The s e l e c t i v i t y towards NMA increased t o 80% a t 4OO0C, w h i l e t h e s e l e c t i v i t i e s t o NNDMA decreased v e r y r a p i d l y as

the

r e a c t i o n temperature increased t o 40OoC. The s e l e c t i v i t y towards NMT s t e a d i l y decreased w i t h increasing r e a c t i o n temperature up t o 4OO0C and became constant above 40OoC. The s e l e c t i v i t y towards NNDMT d i d not change much w i t h r e a c t i o n temperature. According t o t h e NH3 TPD r e s u l t s (Fig. 4 and 51, weak a c i d s i t e s (300 K
600K) are present i n ZSM-5 and (B)ZSM-5. Strong a c i d s i t e s are required t o produce NNDMA and NMT. Weak a c i d s i t e s are a c t i v e s i t e s f o r NMA. Even medium and

weak a c i d s i t e s can produce coke a t high r e a c t i o n temperature. The formation o f coke decreases t h e e f f e c t i v e diameter o f pores r e s u l t i n g i n l e s s formation o f

I100

l/LHSV

TEMPERATURE ('C

(hr)

Fig. 6. E f f e c t o f contact time on t h e a c t i v i t y and s e l e c t i v i t y o f (B)ZSM-5 (60) (N :MeOH:Aniline= 23:3:1, Temp. = 4OO0C, ime on stream = 1 hr, 0 ; A n i l i n e conversion, ;NMA, 0 ;NNDMA, A ; NNDMT, A ; NMT)

?

Fig. 7. E f f e c t o f reactiontemperature on t h e a c t i v i t y and s e l e c t i v i t y o f (B)ZSM-5 (601, Timeon stream= 1 hr.

more s t e r i c a l l y hindered product such as NNDMA and NMT.

-

( i i i ) Effect o f mole r a t i o o f reactants. Upon i n c r e a s i n g t h e r a t i o o f CH30H/ a n i l i n e from 0.3 t o 10 i n t h e r e a c t i o n m i x t u r e by i n c r e a s i n g t h e f l o w r a t e o f CH30H a t constant flow r a t e of a n i l i n e , a n i l i n e conversion increased 31% t o 75% (Fig. 8 ) . This suggested t h a t t h e r a t e o f methylation o f a n i l i n e w i t h methanol i s o f p o s i t i v e order w i t h respect t o methanol. However, t h e v a r i a t i o n i n t h e

n

-0 2

G 8 1 0 Methanol /Aniline

4

Fig. 8. E f f e c t of methanol/aniline mole r a t i o on t h e a c t i v i t y and s e l e c t i v i t y o f (B)ZSM-5(60)(Time on stream = 1hr, Temp. = 35OOC).

W

z 2 20z U

- 0

0

1

2 3 4 TIME ( hr 1

Fig. 9. D e a c t i v a t i o n i n t h e methylat i o n o f a n i l i n e w i t h (B)ZSM-5(60) (Temp. = 4OO0C, m ; LHSV = 1.08 hr-1, 0 ; LHSV= 1.72 hr-1).

I101 concentration o f a n i l i n e under t h e constant f l o w o f MeOH d i d n o t a f f e c t t h e r e a c t i o n r a t e , i n d i c a t i n g t h a t t h e zero-order dependence on t h e concentration o f a n i l i n e i s due t o t h e strong adsorption o f a n i l i n e on t h e a c i d s i t e s on (BIZSM-5 (60). As t h e concentration o f methanol increased, t h e s e l e c t i v i t y towards NMA

s l i g h t l y decreased, w h i l e t h e s e l e c t i v i t i e s towards NNDMA, NMT and NNDMT s l i g h t l y increased.

( i v ) Deactivation. The d e a c t i v a t i o n w i t h r e a c t i o n t i m e on stream i s shown i n Fig. 9. Regardless o f contact time,

(BIZSM-5(60) c a t a l y s t deactivated v e r y r a p i -

d l y . A f t e r 4 hours o f reaction, the a c t i v i t y decreased t o 25% o f t h e i n i t i a l c a t a l y t ic a c t i v i t y

.

( v ) Product d i s t r i b u t i o n s o f (BIZSM-5, ZSM-5 and ion-exchanged (BIZSM-5 i n the a n i l i n e methylation reaction, As t h e mole r a t i o o f Si02/B203 increased, t h e NMT

s e l e c t i v i t y towards NMA increased, w h i l e t h e s e l e c t i v i t i e s towards NNDMA,

and NNDMT decreased (Fig. 10). Comparing t h i s p a t t e r n o f s e l e c t i v i t i e s w i t h NH3 TPD curves (Fig. 41, weak a c i d - s i t e s appear t o produce NAM where medium acids i t e s produce NNOMA and NMT. Table 2 shows t h e product d i s t r i b u t i o n s i n t h e methylation r e a c t i o n catalyzed over ZSM-5's o f d i f f e r e n t Si02/A1203 r a t i o s . As the r a t i o increased, t h e s e l e c t i v i t y towards NMA increased due t o t h e decrease i n t h e number o f strong and medium a c i d - s i t e s . However, t o l u i d i n e , C-alkylate, s t i l l was produced w i t h 294-5 (SiO~/A1203=IlO), and (BIZSM-5 d i d not produce t o l u i d i n e . The r a t i o o f N-alkylate t o C-alkylate increased t o 50 as the

mole

r a t i o o f Si02/B203 increased. (B)ZSM-5 produced l e s s dimethyl-substituted a n i l i n e a t t r i b u t e d from t h e decrease i n t h e porediameter o f (B)ZSM-5 because o f t h e c o n s t r i c t i o n i n t h e u n i t c e l l s i z e o f (BIZSM-5. (BIZSM-5 showed higher s e l e c t i v i t y t o NMA, but deactivated f a s t . (BIZSM-5 (250) was ion-exchanged w i t h Mg2+, Zn2+ and Cu2+ t o study t h e d i f f e r e n c e s i n t h e a c t i v i t y maintenance. The a c t i v i t y maintenance o f these ion-exchanged (BIZSM-5's was presented i n Fig. 11. Among these, Cu(B)ZSM-5 showed e x c e l l e n t a c t i v i t y maintenance, high s e l e c t i v i t y t o NMT and low s e l e c t i v i t y t o NMA (Table 2 ) . Fig. 5 showed t h e NH3 TPD spectra o f H(B)ZSM-5 and Mg, Zn, Cu ion-exchanged (BIZSM-

5's. Ion-exchange o f H(B)ZSM-5 w i t h Mg2+, Zn2+ and Cu2+ decreased both t h e strength and t h e number o f a c i d s i t e s . Cu(B)ZSM-5 has t h e weakest a c i d indicated by t h e lowest .T,

However, t h e high s e l e c t i v i t y t o NMT

sites

cannot be

explained by t h e presence o f weak a c i d s i t e s . It i s necessary t o have medium o r strong a c i d s i t e s t o produce NMT. It could be suggested t h a t b a s i c i t y o r coordination a b i l i t y o f c a t i o n t o a n i l i n e should be i n t i m a t e l y r e l a t e d t o t h e s e l e c t i v i t y towards C-alkylates o r N-alkylates.

I n the case o f Mg(BIZSM-5 and

Zn(B)ZSM-5, t h e s e l e c t i v i t y toward NMA increased due t o t h e smaller number o f medium and strong a c i d s i t e s .

I102

'"I

TIME ( h r )

Si02 I8203

Fig. 11. A c t i v i t y maintenance 8f i o n exchanged (B)ZSM-5 (Temp. = 350 C). (For legend, See Fig. 6.)

Fig. 10. E f f e c t o f SiO2/B 03 r a t i o on t h e product d i s t r i b u t i o n fTemp.-35OOC). (For legend, See Fig. 6.

TABLE 2 Product d i s t r i b u t i o n s i n the methylation o f a n i l i n e by ZSM-5,

(B)ZSM-5 and i o n -

exchanged (B IZSM-5. Catalyst Si02/A12O3 or SiOz/B203 ZSM-5

RXN Temp. ( O C I

NMA

NNDMA NMT NNDMT

T

-

-

13.0 8.0 2.0 2.0

11.0 2.0

22

3

1

19

3

76

2

-

83

15

0

2

-

30 50 110

420 420 420

13.6 37.2 20.0 45.0 77.0 12.0

60 250 6 50 1300

350 350 350 350

60.0 68.0 81.0 85.0

16.0 22.0 17.0 13.0

Mg(B) ZSM-5

250

350

75

Cu(B) ZSM-5

250

350

Zn(BI ZSM-5

250

350

(B)ZSM-5

N-a1 k y l a t e dimethyl

Selectivity ( X )

-

49.2 35.0 11.0

-

C-alkylate mnomethyl 1 1.85 8.1

0.59 0.82 0.14

4.2 9.0 50 50

0.48 0.44 0.23 0.18

CONCLUSION (BIZSM-5 showed higher s e l e c t i v i t y t o NMA than ZSM-5 due t o t h e weaker a c i d i t y o f (BIZSM-5 and smaller pore s i z e than ZSM-5. C o r r e l a t i o n between a c i d s i t e s measured by NH3 TPD w i t h t h e product d i s t r i b u t i o n s o f methylated a n i l i n e s showed

1103 t h a t s t r o n g a c i d s i t e s (T,$600K),

medium a c i d s i t e s (450
and weak

a c i d s i t e s (T,,~450) are a c t i v e s i t e s f o r producing C - a l k y l a t e and coke, and NMT, and NMA, r e s p e c t i v e l y . As t h e mole r a t i o o f B203/Si02 increased, p o r t i o n s o f medium a c i d s i t e s decreased r e s u l t i n g i n t h e

higher

NNDMA

the

selectivity

towards NMA. I o n exchange o f (B)ZSM-5 w i t h Mg2+, Cu2+ and Zn2+ caused t h e number and s t r e n g t h o f a c i d s i t e s i n (BIZSM-5 t o be decreased. The s e l e c t i v i t i e s towards NMA w i t h Mg(B)ZSM-5 and Zn(B)ZSM-5 higher t h a n t h e corresponding (B)ZSM-5

are

due t o t h e a c i d s i t e s weaker t h a n those o f (BIZSM-5. However, Cu(B)ZSM-5

of

weakest a c i d s i t e s among them has 76% s e l e c t i v i t y t o NMT and showed an e x c e l l e n t c a t a l y t i c a c t i v i t y maintenance, which cannot be explained by t h e a c i d i t y o n l y . This unusual f a c t must be r e l a t e d t o t h e b a s i c i t y o f c o o r d i n a t i n g a b i l i t y

of

a n i l i n e t o cu2+ i o n . REFERENCES 1 L.K. Doraiswamy, G.R.W. Krishnan and S.P. Mikherjee, Chem. Eng., 88 19811 78. 2 M. Onaka, K. Ishikawa and Y. Izumi, Chem. Lett., (1982) 1983. 3 A.G. H i l l , J.H. Shipp and A.J. H i l l , Ind. Eng. Chem., 43 (1951) 1579 4 J.M. Parera, A. Gonzalez and M.A. B a r r a l , I E EC Prod. Res. and Dev. 7 (1968) 259. 5 G.O. Chivadze and L.Z. Chkheidze, Izu. Acad. Nauk. Gruz. SSR, Ser. Khim., 10 (1984) 232. 6 P.Y. Chen, M.C. Chen, H.Y. Chu, N.S. Chang and T.K. Chuang, i n Y. Murakami, A. I j i m a and J.W. Ward ( E d i t o r s ) , Proc. 7 t h I n t . Z e o l i t e Conf., Tokyo, Japan, August 17-22, 1986, E l sevier, Amsterdam, 1986, pp. 739-746. 7 M.G. Howden, Z e o l i t e s , 5 (1985) 334. 8 L.M. Bibby, L.P. A l d r i d g e and N.B. Milestone, J . Catal., 72 (1981) 373. 9 W.J. B a l l , J. Dwyer, A.A. G a r f o r t h and W.J. Smith, i n Y. Murakami, A. I i j i m a and J.W. Ward ( E d i t o r s ) , 7 t h I n t . Zeol. Conf., Tokyo, Japan, Auguest 17-22, 1986, Elesevier, Amsterdam, 1986, pp. 137-144. 10 G. Coudurier and J.C. Vedrine, i n Y. Murakami, A. I i j i m a and J.W. Ward ( E d i t o r s ) , Proc. 7 t h I n t . Z e o l i t e Conf., Tokyo, Japan, August 17-22, 1986 E l sevi er, Amsterdam, 1986, pp. 643-652. 11 S.B. Hong, S.I. Woo, J.K. Lee and Y.S. Uh, submitted t o Z e o l i t e s (1988). 12 Z. Gabelica, J.B. Nagy, P. Bodart and G. Debras, Chem. L e t t . (1984) 1059. 13 A.B. Brown and E.E. Reid, J. Am. Chem. SOC., 46 (1924) 1836. 14 A.G. H i l l , J.H. Shipp and A.J. H i l l , Ind. & Eng. Chem., 43 (1951) 1579.