Deuteracion de Aromaticos

8/10/2019 Deuteracion de Aromaticos

1/7

A SIMPLE EM FOR THE SYNTHESIS OF PERDEUTERATED

AROMATIC HYOROCARBONS AND HETEROCYCLIC COMPOUNDS

Stev en B. Hawthorne, Da v i d

J . M i l l e r ,

Ted R.

Aulich,

and S y l v i a A. Farnum

U l i v e r s i t y of N o r t h D a k o t a E n er gy R e s e ar c h C e n t e r

Box

8213 U n i v e r s i t y S t a t i o n

&and Forks, North D a k o t a 58202

ABSTRACT

A

g e n e r a l m eth od h as be en d e v e l o p e d f o r t h e p r e p a r a t i o n of d e u t e r a t e d

a r o m a t i c compounds t h a t a r e u s e f u l f o r c o a l r e a c t i o n s t u d i o s and as i n t e r n a l

s t a n d a r d s f o r

GC/MS

a n a l y s i s . The method r e q u i r e s l i t t l e s p e c i a l i z e d

equipment o r s y n t h e s i s e x p e r t i s e . A r e a c t i o n m i x t u r e c o n t a i n i n g

D C l , D2n,

and

c hro miu m i s us ed t o e x ch an ge d e u t e r i u m f o r a r o m a t i c h y dr og en s a t t e m p e r a t u r e s

o f ?Ono t o 300OC.

A

s i n g l e s e t o f r e a c t i o n c o n d i t i o n s ca n he us ed t o p r e p a r e

a w id e r a n g e o f d e u t e r a t e d a r o m a t i c s

with

n e a r l y c o m p l e t e ex ch an ge o f a r o m a t i c

h yd ro ge n f o r de u te r i um and l i t t l e o r

no

c h em i ca l d e g r a d a t i o n o f t h e

r e a c t a n t . When a 2 D : l m o l a r r a t i o o f d e u t e r i u m t o a r o m a t i c h y d r o g e n was u s e d

t h e i s o t o p i c p u r i t y o f m o st sp ec ie s t e s t e d i n c l u d i n g p h en an th re ne ( i s o t o p i c

p u r i t y

o f

94%), pyrene ( 9 5 ) , p h e n o l (96 ), d i b e n z o f u r a n ( 9 6 % ) , c a r b a z o l e

(94x1, and d i benz oth io phen e (939; ), approached t h e H/D exchange equi

1

r i u m o f

9 5% i n t w o t o f i f t e e n h o u rs . The m eth od a l s o w ork s w e l l w ith c o m p l e x m i x t u r e s

a s d em o n st ra te d by t h e d e u t e r a t i o n o f a r o m a t i c s i n a c o a l - d e r i v e d a n t h ra c e n e

o i l .

INTRODUCTION

The u se o f d e u t e r a t e d a r o m a t i c o r g a n i c com pounds as i n t e r n a l s t a n d a r d s f o r

t h e e v a l u a t i o n o f s am ple p r e p a r a t i o n p r o c e d u r es and f o r t h e a n a l y s i s o f

comp lex samp les us in g gas ch romatography c ou p le d w i t h mass sp ec t ro me t r y

(GC/MS) c a n g r e a t l y i n c r e a se t h e a cc ur ac y o f a n a l y t i c a l r e s u l t s w h i l e o f t e n

r e d u c i n g t h e t i m e r e q u i r e d f o r t h e a n a l y s i s . D e u t e r a t e d com pounds a n d

m i x t u r e s a r e a l s o u s e f u l

f o r s t u d y i n g t h e f a t e o f o r g a n i c com pounds i n complex

s ys te ms su c h as c o a l c o n v e r s i o n r e a c t i o n s . U n f o r t u n a t e l y , t h e w i de s p re a d u s e

o f d e u t e r a t e d compounds i s l i m i t e d by t h e i r h i g h c o s t and t h e l a c k o f

a v a i l a b i l i t y o f many com pound c l a s s e s .

The p u rp o se of t h i s p a pe r i s t o d e s c r i b e a g e n e ra l m e th od f o r t h e

s y n t h e s i s

o f

d e u te r at e d s pe c ie s t h a t i s a p p l i c a b l e t o s e v e ra l c l a s se s o f

a r o m a t i c compounds, r e q u i r e s m i n im a l t i m e and s y n t h e s i s e x p e r t i s e , y i e l d s a

c h e m i c a l l y and i s o t o p i c a l l y p u r e p ro d u c t, u se s s i m p l e and i n e x p e n s i v e

equipment and rea ge nts , and can he used

w i t h

c a n p l e x m i x t u r e s . T h i s m e th o d

a l s o y i e l d s p ro du ct s w i t h m u l t i p l e d e u t e r i u m w hich i s d e s i r a b l e t o a v oi d t h e

o v e r l a p

i n

t h e m ass s p e c t r a t h a t o c c u rs

from 1 3 C

i s o to p e peaks and (M-H)' i o n s

when u n l a b e l e d a nd m n o d e u t e r i o - l a b e l e d c om pou nd s o c c u r i n t h e same s a m pl e

1). The s y n th e s is i s s i m i l a r t o t h e method of Wers t iuk and Kada i ( 2 - 6 ) f o r

t h e H/D e xc ha ng e o f a r o m a t i c p r o t o n s w i t h

D,o/DCl

e x c ep t t h a t chrom ium i s

added t o i n cr ea s e t h e r a t e o f H D exchange. The a b i l i t y o f t h i s m eth od t o

p r o v i d e c h e m i c a l l y and o t o p i c a l

l y

p u r e p e r d e u t e r a t e d p ro d u c t s was e v a l u a t e d

47


2/7

f o r s e v e r a l a r o m a t i c h y d r o c a rh o n s and 0-, S-, a n d N - c o n t a i n i n g a r o m a t ic s . Th e

m e th od was a l s o u s ed t o p ro du ce p e r d e u t e r a t e d d e r i v a t i v e s o f t h e co mp on en ts o f

a c o a l - d e r i v e d a n t h r ac e n e o i l .

EXPE

RIMEM A L

A l l r e a c t i o n s w ere p e rf or m ed i n 10 m 0.d. (8 mm i .d . ) x a p p r o x i m a t e l y

cm l o n g p y r e x g l a s s t u b e s . One en d o f t h e t u b e was s e a l e d w i t h a f l a m e h e f o r e

a d d in g t h e r e ag e n ts . The r e a c t i o n m i x t u r e was t h e n f r o z e n i n l i q u i d n i t r o g e n ,

t h e tub e was evacua ted us in g a sma l l l a b or a t o ry vacuum pump, and th e tuh e was

s e a l e d w i t h a f l ame.

T h i s p ro ce du re f i l l e d a p p r o x i m a te l y o n e- h al f o f t h e t u b e

v ol um e w i t h r e a ge n t s . The s e a l e d t u b e s w er e t h e n p l a c e d i n t o a 1.3 cm 0.d. x

15 cm s t a i n l e s s s t e e l p i p e . B e f o r e c a p p i n g t h e p i p e w i t h "Sw ag elo k" f i t t i n g s ,

a p p r o x i m a t e l y 2 mL o f wa te r was added

so

t h a t t h e p r e s s u r e i n s i d e and o u t s i d e

o f t h e g l a s s r e a c t i o n t u b e wo ul d be a p p r o x i m a t e l y eq ua l d u r i n g h e a t i n g . As a

s a f e t y m easure, t h e s t a i n l e s s s t e e l p i p e was p l a c e d i n s i d e a c o nt ai nm e nt

v e s se l made f r o m a o n e - in c h d i a m e t e r t h i c k - w a l l e d i r o n p i p e w i t h t h r e a d e d e nd

caps.

A

s m a ll h o l e was d r i l l e d t h r o ug h one of t h e end c ap s t o a v o i d a

p r e s s u r e i n c r e a s e i n t h e c o n t a i n m e n t ve s s el . The e n t i r e a p p a r a tu s was t h e n

h e a t e d t o 200-30O"C f o r an a p p r o p r i a t e t i m e p e r i o d i n t h e o v en o f a g as

c hr om a to gr ap h. C a u t i o n : S i nc e c h l o r i d e i o n d eg ra de s t h e s t r e n g t h o f

s t a i n l e s s ste el , t h e s t a i n l e s s s t e e l p i p e s h o u l d b e r e pl ac e d i f a g l a s s t u b e

b r ea k s d u r i n g t h e r e a c t i o n . The d e u t e r a t io n r e a g e n t c o n s i s t e d o f

4

DC1 (by

w t .

i n

D?O

( b o t h

>

99 i s o t o p i c a l l y p u r e) w i t h 1 0 mg/mL c hro mi um m et al .

S i nc e t h e d i s s o l u t i o n o f t h e ch ro miu m m e t al e v o l v e s h yd ro ge n g as , t h e a d d i t i o n

o f c hr om iu m was pe r fo r me d i n a v e n t i l a t e d h oo d. A f t e r t h e c hr om iu m had

d i s s o l v e d ( a p p r o x i m a t e l y one h o u r ), t h e re a g e n t m i x t u r e was pu rg e d b r i e f l y

w i t h h e l i u m t o re mo ve d d i s s o l v e d hy dr og en . T he r e a g e n t c o u l d t h e n be s t o r e d

i n d e f i n i t e l y i n a d e s ic c a to r .

U n le s s o t h e r w i s e n ot ed , t h e d e u t e r a t i o n o f t h e i n d i v i d u a l p u r e compounds

was per formed us in g a weighed amoun t o f approx imate ly 100 mg o f t e s t s p e c i e s

a nd an a p p r o p r i a t e v olu me o f d e u t e r a t i o n r e a g e n t t o

g i v e a

2O:l

m o la r r a t i o o f

reagen t deu te r ium to exchangeab le p ro tons . Each o f t h e pu re compounds

was

r e a c t e d a t 300C f o r 2 h r a n d / o r

15

h r . I f s i g n i f i c a n t c he mi ca l d e gr a d a t i o n

o c c u r r e d a t t h i s t e m p e r a t u r e , an a d d i t i o n a l s y n t h e s i s was p e rf or me d a t 200C

f o r 2 h r . The d e u t e r a t i o n o f t h e a n t hr a c en e o i l was p e rf or m ed u s i n g 50 mg o f

s a m p l e w i t h 1.0 mL o f d e u t e r a t i o n r e a g en t .

GC/MS a n a l y s i s o f t h e d e u t e r a t e d p r o d u c t s was p e rf or me d w i t h a H e w l e t t -

Packard model 59858 u s i n g a 30 m x 0.32 mm i.d. ( l u m

f i l m

t h i ckness ) DB-5

fu se d s i l i c a c a p i l l a r y c olumn ( J S c i e n t i f i c , R an ch o C or do va , C.A. . A l l

a n a l y s e s we re p e rf o rm e d i n t h e e l e c t r o n i m p ac t mode w i t h

7 0

e V i o n i z i n g

v o lt ag e . I s o t o p i c p u r i t y o f t h e p r o d u c ts was c a l c u l a t e d f ro m t h e r e s u l t a n t

s p e c t r a .

Gas

c h ro m at og ra p hy w i t h fl am e i o n i z a t i o n d e t e c t i o n FID) was

Per fo rmed on a Hew le t t -Packard mode l 5890

GC

w i t h t h e same t y p e o f

ch romatograph ic co lumn as used fo r

GC/MS.

Chem ica l p u r i t y o f t h e s t a r t i n g

m a t e r i a l s and t h e p r o d u ct s was d e t e n i n e d hy GC/FID a n a l y s i s u s i n g

g r a v i m t r i c a l l y p r e pa r e d s o l u t i o n s o f s t a n d a r d and p r o du c t s pe c ie s . P r o to n

NMR

a n a l y s e s o f t h e d e u t e r a t e d o r o d u c t s w ere o e r f o n e d o n a V a r i a n mo de l XL-

200.

t e t r a m e t h y l s i l a n e .

The d e u t e r a t e d p r o d u c t s ' were d i s s o l v e d i n CD2C12 con ta in ing

0.25

4 7 2


3/7

Sinc e mos t o f th e t e s t compounds

( e x c e p t t h e N - c o n t a i n i n g b as es ) w e re n o t

s o l u b l e i n t h e r ea ge nt , q u a n t i t a t i v e r e c o ve r y o f t h e p r od u ct s was e a s i l y

a t t a i n e d by p i p e t t i n g o f f t h e l i q u i d p r o d uc t s o r by r em ov in g t h e r e ag en t fr om

t h e s o l i d p r o d u c t s w i t h a P as t eu r p i p e t t e . The s o l i d p r o d u ct s w er e washed

w i t h w a t e r and d r i e d t o remove t h e r e s i d u a l re a ge n t. The N - c o n t a i n i n g

a r o m a t i c b as es ( a n i l i n e a n d q u in o l i n e ) w er e re mo ve d f r o m t h e r e a g e n t b y m a k in g

t h e r e a c t i o n m i x t u r e b a s i c w i t h 2N NaOH and e x t r a c t i n g w i t h m e t hy le ne

c h l o r i d e . S i nc e t h e p u rp o se o f t h i s s y n t h e s i s m et ho d was t o p r o v i d e l a b e l e d

P r od u ct s w i t h de u te r i um s u b s t i t u t i o n i n c h e m i ca l l y s t a b l e p o s i t i o n s , t h e

h y d r o x y l d e u t e r iu m o n t h e t w o ph e n o l s , a nd t h e t wo a mine d e u t e r i u m on a n i l i n e

w er e e xc ha ng ed f o r p r o t o n s f rom H 20 b e f o r e b e i n g a na l yz e d f o r t h e i r i s o t o p i c

p u r i t y .

RESULTS

AND DISCUSSION

The success o f H /D exchange us in g t h e DC1/D20/ch romium reage n t i n

s y n th e s i z i n g p e r d e u te r a te d a r o m a t i c ca np ou nd s

from

s e v e r a l c an po un d c l a s s e s i s

shown i n T a b l e I Mass s p e c t r a o f s e v e r a l r e p r e s e n ta t i v e com pounds b e fo r e an d

a f t e r d e u t e r a t io n a r e shown i n F i g u r e 1. H/D e x ch a ng e s w i t h e t h y l h en ze ne ,

p h en a nthr en e , py re n e, p e r y l e n e , b i p h e n y l , p h e n o l , d i b e n z o fu r a n , a n i l i n e ,

c a r b a z o le , and d i be n z o t h io p h e n e a l l a pp ro ac he d e q u i l i b r i u m w i t h t h e d e u t e r i u m

p o ol (assumed t o b e 95 % i s o t o p i c p u r i t y ba se d o n t h e 2 0 : l m o l ar r a t i o o f D/H)

i n e i t h e r tw o o r 1 5 h o u r s w i t h no s i g n i f i c a n t c he m ic al d e gr a d at i on . The

i s o t o p i c p u r i t y o f t h o se s pe c ie s t h a t a t t a i n exchange e q u i l i b r i u m ( 95 %

i s o t o p i c p u r i t y ) c an be i mp ro ve d, i f

d e s i r e d ,

hy

i nc r ea s in g t h e r a t i o o f

r e a g e n t D t o e x ch a ng e ab l e

H

o r by p e r f o r m i n g m u l t i p l e e xc han ge r e a c t i o n s .

Q u i n o l i n e a l s o showed n o c h em i c al d e g r a d a ti o n , b u t was o n l y 7 3% i s o t o p i c a l l y

p u r e a f t e r 1 5 h ou rs . However, s u c h p r o d u c t s can s t i l l be u s e f u l f o r i s o t o p e

d i l u t i o n a n a l y s i s . F o r example, t h e

mass

s p ec t ra o f 73% i s o t o p i c a l l y p u re

q u i n o l i n e - d 7 has a b ase peak o f 1 3 4 c om pa re d t o 1 2 9 f o r u n d e u t e ra t e d q u i n o l i n e

and, s i n c e n o d e t e c t a b l e o v e r l a p i n t h e i r mass s p e c t r a o c cu r s i n t h e m o l e c u l a r

i o n r e gi o n, t h e 73% i s o t o p i c a l l y p ur e p ro du ct i s s t i l l u s e f u l as an i n t e r n a l

s t a n d a r d ( F i g u r e

1 .

L on ge r r e a c t i o n t i m e s a n d / o r h i g h e r r e ag e nt 0 t o

r e a c t a n t H r a t i o s c o u l d be used t o i n cr e as e t h e i s o t o p i c p u r i t y .

O n ly t h r e e s p e c ie s , 2 , 4 - d im e th y lp h e n o l, a n i s o l e , and 2 - m e th y l t h i o p h e n e ,

showed e noug h d e g r a d a t i o n t h a t t h e s y n t h e s i s a t 300C was jud ged t o be

u n s u i t a b l e . M i l d e r c o n d i t i o n s o f 200C f o r 2 h r . w ere us ed f o r each o f t h e s e

s p e c ie s i n an a t t e m p t t o r e d u ce d e g r a d a t i o n . Bo th 2 ,4 - dim e th ylp h e no l a n d 2 -

m e t h y l t h io p h e n e we re r e a s o n a bl y s t a b l e u n de r t h e s e c o n d i t i o n s and y i e l d e d

p ro du ct s w i t h i s o t o p i c p u r i t i e s o f 8 9% a nd 85 , r e s p e c t i v e l y ( T a b l e I . The

m e th y l h y d ro g en s o f 2 - m e th y l t h i o p h e n e e xc ha ng ed r e a d i l y and w e re i n c l u d e d i n

t h e c a l c u l a t i o n o f i s o t o p i c p u r i t y . A n i so l e c o nt in u ed t o be c o nv e rt e d t o

p he no l e ven a t t h e se m i l d e r c o n d i t i o ns w i t h o n l y 43% o f t h e o r i g i n a l a n i s o l e

r e m ai n in g a f t e r t h e r e a ct i o n . Under t h e s e c o n d i t i o n s , o n l y t h r e e p o s i t i o n s o n

a n i so le unde rwent s i g n i f i c a n t H/D exchange. These po s i t i on s were shown by 200

MHz p r o t o n NMR t o be t h e o r t h o - a nd p a r a - p o s i t i o n s , as w ou ld be e xp e ct e d s i n c e

t h e methoxy gr ou p a c t i v a t e s t h o s e p o s i t i o n s f o r e l e c t r o p h i l i c s u b s t i t u t i o n .

The same r e s u l t i s o b ta i n e d when p h e no l u nd er go es t h e s y n th e s i s a t 2 0 D Y f o r 2

h r .

Th ese r e s u l t s i n d i c a t e t h a t t h i s me th od may b e u s e f u l t o p r od u ce a r o m a ti c

compounds l a b e l e d a t s p e c i f i c ( o r t h o - , p a r a - vs. m e ta -) p o s i t i o n s by c a r e f u l

s e l e c t i o n o f t h e r e a c t i o n t e mp er at ur e.

473


4/7

The us e o f t h i s

s y n t h e s i s t o p ro du ce p e r d e u t e ra t e d d e r i v a t i v e s i n com plex

m i x t u r e s was d e m o n s tr a t ed w i t h a c o a l d e r i v e d a n t hr ac e ne o i l c o n t a i n i n g

p r e d o m i n a n t l y a r o m a t i c h y d ro c a rb o n s. F i g u r e

2

s ho ws t h e r e s u l t s o b t a i n e d when

t h e a nth ra ce ne o i l

unde rwent H/D exchange f o r 2 hours a t 300C. N3 d e t e c t a b l e

c h em i ca l d e g r a d a t i o n o f t h e s am pl e o c c u r r e d a s d e t e r m i n e d b y a c a n p a r i s o n o f

t h e G C / F I D c hr om at og ra ms o f t h e o i l b e f o r e and a f t e r t h e s y n t he s i s. The

m o l e c u l a r i o n r e g i o n s o f t h e mass s p e c t r a o h t a i n e d b e f o r e and a f t e r t h e

s y n t h e s i s a r e shown f o r s e v e r a l r e p r e s e n t a t i v e s p e c i e s ( F i g u r e 2 ). The

i s o t o p i c p u r i t i e s we re n a p h t h a le n e ( 97 % ), d i h e n z o f u r a n ( 9 8 %) , d i h e n z o t h i o p h e n e

(99%), phe nan th ren e (96%), and py re ne (97%). A romat i c compounds ha v in g

a l i p h a t i c p r o t o n s a l s o s howed n e a r l y q u a n t i t a t i v e e xc ha ng e o f a r o m a ti c p r o to n s

f o r d e u t e ri u m , a nd some e xc ha ng e o f t h e a l i p h a t i c p r o t o n s . F o r e xam ple , t h e

b as e peak f o r 2 - m e th y l na p h t ha l e ne - d 7 ( i f o n l y a r o m a t i c p r o t o n s e xch ang ed f o r

D) would be a t m/z 149. The in te ns e peaks a t m/z 15 1 and 152 show t h a t some

a l i p h a t i c p r ot o n s a l s o e xc ha nge d ( F i g u r e 2 .

The r e s u l t s o f t h e p e r d e u t e r a t i o n s t u d i e s o f p u r e co mp ou nds ( T a b l e I a n d

t h e a nt hr ac en e o i l d e m on s tr a te t h a t t h e m e th od p r es e nt ed h e r e i s u s e f u l f o r

s y n t h e s i z i n g p e r d e u t e r a t e d a r o m a t i c com po un ds f r o m s e v e r a l co mpou nd c l a s s e s a s

w e l l as i n c om ple x m i x t u r e s . A l l o f t h e s p e c ie s t h a t have been t e s t e d y i e l d

p ro du ct s w i t h b o t h h i g h i s o t o p i c p u r i t y an d ( ex c ep t f o r a n i s o l e ) h i g h c h em ic al

p u r i t y . The c o s t o f t h e re ag en t i s l o w ( l e s s th a n 20 d o l l a r s f o r t h i s e n t i r e

s t u d y ) and t h e s y n t h e s i s i s s i m p l e t o p er fo rm .

CRED I T

The a u t h o r s w o ul d l i k e t o t h a n k t h e

U.S.

D ep art me nt o f E ne rgy f o r p a r t i a l

su pp or t o f t h i s work unde r co nt ra ct number DE-FG22-86PC90911.

REFERENCES

1.

B l o m ,

K.; Schuhardt , J . ; Munson, B. Anal. Chem. 1985,

57

1986-1988.

2. Werst iuk ,

N.H.;

K ad a i, T. Can.

J .

Chem. 1973,

51

1485-1486.

3.

Wers t iuk ,

N.H.;

Kadai, T. Can. J Chem. 1974, 52 2169-2171.

4. W e rs ti u k, N.H.; Ya dai ,

T.

I n "P ro ce ed in gs o f t h e F i r s t I n t e r n a t i o n a l

C on fe re nc e o n S t a b l e I s o to p e s i n C h em i st ry , B i o l o g y , a n d M e d i ci n e "; K l e i n ,

P.Y.; Pete rson , S.V . ; Eds; 1973, N T I S CONF-730525, pp. 13-19.

5.

6.

W e r s t i u k ,

N.H.;

Timmins,

G.

Can.

J.

Chem. 1981,

59

3218-3219.

Wers t iuk ,

N.H.;

Timmins,

G.

Can. J . Chem. 1981, 51 1485-1486.

474


5/7

Tab le I

Syn thes i s o f Pe rd eu te r a ted Arom at ic Compounds

e th y l b en ze ne

phenan th rene

b ip h e n y l

py rene

p e r y l ene

phenol

2 ,4 -d ime thy l pheno l

a n i s o l e

d i b e n z o f u r a n

a n i l i n e

q u i no1i e

c a r b azo 1e

E-me thy lt

h i

ophene

d ib en zo th i ophene

na

5

10

10

10

12

6

4

5

8

7

7

8

6b

8

I s o t o p i c P u r i t y

(%)

2 h r 1 5 h r 2 h r s

3o0c 3n0c m n 0 c

50 97

94 94

84 96

- 95

-

95

94 96 100'

89

- - 97c

52 96

95 96

29 73

93 94

-

-

85b

95 93

C h e m i c a l P u r i t y ( % )

2

h r 1 5 h r

2

h r

3nnoc 3on0c 2nnoc

inn

i n o

i o n inn

i o n

9 5

-

100

-

100

88 39

100 99 100


6/7

Bef or e Deuteration After Deuteration

2 0 2

d,. -pyrene

yrene

4 0

20 2

106

:j, , ,

~

, , , . , ;, ,

11

,

.

.

. : :I. . . . :. .

40

8

80

100 120

140 I60

180 2

220 10

6 8

100 120 140

160 8 ZOO 220

2

40 6 80 100

120

1

i

i

40 I I II

212

192

I

00

64

I d,-dibenzothiophene

C

-

100

dibenzothiophene

- ii

. , , , , , .T.,

;,, , , , ,

I .

Deuteracion de Aromaticos

Documents

Transcript of Deuteracion de Aromaticos