MHSMP-70-16

I

A

SYNTHESIS OF PICRYL CHLORIDE

D. V. Hayes & F. I. Honea

July 1970 P. 0. NO. 93-1840

for

Sandia Corporation

Sandia Laboratory Albuquerque

cc

P. 0. BOX 547 ,MARILLO, T€XAS 79105

806-335-1581

u. s.

operated for the

AlUMiC ENERGY COMMISSION under

GOVERNMENT Contract DA-ll-173-AW-

DISCLAIMER

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsi- bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Refer- ence herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recom- mendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

DISCLAIMER

SYNTHESIS OF PICRYL CHLGRIDE

1

V 4 V . /fugu E F. 7 . Honea

I

July 1570 Purchase Order 93-1840 -- - ---- _._ -

- - .

-- .

- - - _ -- ABSTRACT

A t o t a l o f six pi lot-scale batches o f picryl chloride were made. i'ncluded three 5-kg batches and three 10-kg batches.

These

The three 5-kg batches were made t o invest igate the 'problems encountered v i < ~ i ? actual production and materials h a n d ) i n g . t o study the process parameters and the yield prob?eir!s or1 g i nal ly encountersd w i t h the 5-kg batches,

The yields on the 5-kg batches ranged from 40 t o 60% of approximately 59% puri ty . . T h e y ie lds on the 10-kg batches were 80, 86 and 91% i n chrono1og;czi order. ?he pur i t ies were 95, 99,+ and 9 9 i percent respecti ve'ly.

Di s t r i b u ti: on :

L. D. S m f t h , S a n d i a Lab., Org. 2300 - 1 copy M. T. Abegg - Acm: C , A, K:edgaard/D. M, O'Keefe, S a n d i a Lab., Or5. 234 C. B. McCanpbe'i - A t t n : H. M, Barriett, Sand-ia Lab., Org. 2310 Wynne K. Cox, S a n d i a Lab, Library - 1 copy John Kury - Attn: EdNard Games, J r , , Lawrence Radiatiofi Lab, - 1 cap) Piant Manager, 13uYlington AEC Plant - 1 copy R , L e Ho*brnSerg, Burlington AEC Plant - 1 copy

W. H. Lawrence, Albuquerque Operations Office - 1 copy

The three 10-kg batches were mcie

-Director of Development, Pantex P l a n t - 4 copies ( & : ( ; i f - C,f%j

C i rcul a t i on Copy

John C. Drummond, P l a n t Manager - A t t n : D. R . Dunham R. B. Jewel], Vice-president

C i rcu7 titi on Copy

(1) Area Manager, AEC/AAO ( 2 ) Division Manager, Engineering ( 3 ) Division Manager, Quality (4) Di-vi s i on Manager , Manuf ac ttiri n g

7'

T A B L E O F C O N T E & T S

A

D i s cuss ion . . . . . . . . . . . . . . . . . . . . . . . . . Frocedure.

Source and Qua l i ty of Katerials.

Equipment.

Calua ted Temperatures of Reac t ions . . e e .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . , .

Future Work; Corrcnents; Conclusions. . .- ._ . . . . . . . . . - . ---. -

- - - - - _ . FiSures --- , - . - . . . . . . . . . . . . . . . . . . . . . . . . .

. I , ,, 2

DISCUSS I ON

The synthesis o f picryl chloride is a two s tep riactiori:

reacted w i t h pyri dine t o form pyri di nium p i c ra te w h i c h i s c h l o r i nat'ed wi.th 5r;ss-

phorus oxychl ori de t o form the pi cryl chf ori de.

f i r s t p i c r i c acid i s

'

I NO2

Pic r i c Acid

Pyri dine

Pyri d i n i urn P i c ra te -l. POCl.3 DMF ->

. - I ii02

P i cryl C h l G r i 50

The basic procedure used was t h a t provided by Sandia i for laboratory schle

(50 gm) work. -, Several var ia t ions o f ' c h i s basic procedure were t r i e d . , 1 7 2 2f;-

cedure which produced the best qual i ty also had the highest y i e?d ,

'.Dr. David M, C'Keef&, Ora. 2341

- . - . :... . . - - -

. *

--. . .-

. .- .

I . Procedure

The p i c r i c acid is dissolved i n about one-half the required dirr:trljj

formamide (DMF) and f i l t e r e d before being ’placed in the 2 0 0 - t i w r 5 . e ~ c z r .

The r e s t o f the DMF i s then added t o the reactor.

The pyridine i s then mixed w i t h the required DXF and poured rc;-.d:j sr,t=l

the p i c r i c acid/DMF solution and allowed t o mix fo r a b o u t one h w r v/:ck

agi ta t ion (150 rpm). The temperature r i s e on addition of tFle >yr-.c;r*e :.r.s

between 5 and 10°C for a l l batches. Heat o f reactions have DEE: c z l c z -

la ted from this data and compared to theoretical values (Sect7o:. I!:

The phosphorus oxychloride is added t o the reaction mixture tnrous?: G

polyethylene tube w h i c h extends just below the surface o f the r ~ a c z - ~ r , r

m9xture. Addition times varied between 58 and 26 minutes. C O : ~ U.Z:-C-T

(21-22°C) is c i rculated t h r o u g h the lower reactor cooling c57ls ( 6 ~ 3 :- - < -’

during the POC13 a d d i t i o n .

by use o f a metering pump-.

The f low r a t e reproducibilfTy could tc, i - C ; - ’ C E C

The heat of reaction has been caici l ;a t~.r : < , - E

compared t o theoreti cal va

T ~ V O procedures were t r ied a t this p o i n t . The preferred method ~ 2 % :?

l e t the mixture s t a n d overnight w i t h ag i ta t ion , The reaction i n i x ~ ~ r e 7s

then pulled from the 200-Liter t o the 200-Gallon Reactor where 2 2 sc+:.r:-c’

hydrochloric acid b a t h has been prepared.

as possible (120 rpm).

to 3 hours w i t h hot water (5.0 gpm, temperature - 48‘C), then z;:3:.: ;T

mixture t o cool overnight before dumping i t in to the HCi bath as & s : : - ~ s G

The agi ta t ion is as viclen-,

The other method was t o heat the r n i x t t r e fc:- 2

The p i c r y l c h l o r i d e remains i n the HCl ba th f o r abou t 30 minutes W?GE

f i l t r a t i o n can be completed.

of de ion ized w a t e r and a i r d r i e d f o r about one hour .

is then vacuum dried f o r 48 hours o r u n t i l d r y ,

The s o l i d s a r e then wsshed w i t h 50 ~ S ; ~ O I : S

The p i c r y l c h l ~ r i d e 4

t

‘The i n c r e a s e i n both yield and p u r i t y t h a t was achieved w i t h ;he I C -

kilograin batches compared t o the 5-kilogram ba tches appea r s t o ;;? ;?? :rf

f o u r major f a c t o r s . First, the r e a c t i o n mixture was al lowed t o str.r,c;

w i t h a g i t a t i o n for approximately one hour prior t o the P W 1 , adc;T--,cr:.

Second, the POCl3 a d d i t i o n was made milch slower and i t was i i :s rel ,c~c

through a polye thylene tube w h i c h ex tended just below t h e rezct-;

, .

T h i r d , a f t e r the POC13 a d d i t i o n was complete , the mixttire wcs 2 ; i ~ / 2 ~ ;c

s t a n d ove rn igh t be fo re b e i n g added t o the HC1 s o l u t f o n . Four-Lh , t:.i r C f i l t r a t i o n time was reduced from 24 hours on the f i r s t ba tch t o z b m t A

minutes f o r the 10-ki logram ba tches .

The primary tes t f o r p u r i t y was t h me l t ing p o i n t .

appa ra tus was used f o r these de te rmina t ions . TA’s ( F i g s . 3 , 4, i n c 3:

were a l s o run on the solids and compared t o Sand ia - fu rn j shed s m ? ~ e s

( F i g , 2 ) .

A Hoover K Z ~ : I Z ; F C - Y :

Samples of the three 10-kilogram ba tches were t i t r a t e d ,V{T?. 2

sodium hydroxide s o l u t i o n t o determine p u r i t y . The sampies were 9;szec’

i n w a t e r and al lowed t o s t a n d about 1 t o 2 minutes t o i n s u r e a l l 3 i c r i c

a c i d i n the sample was d i s so lved .

t i o n t o determine the amount o f p ic r ic a c i d i n each s o l u t i o n , Si::ce c,;c:-,~:

I t was then t i t r a t e d w i t h an M!ti s z : ~ i -

c h l o r i d e hydro l i zes s lowly t o picr ic a c i d , the anount of p ic r ic ic:6 s’-.c:.!:

by the t i t r a t i o n should be more than was a c t u a l l y there as an ir.;x!--,:y,

-4-

11. Source and Quality of Materials

I

Kateri a1 Source q u a i i t y

Picr ic Acid Southern Dyes tuf f Company Technical Grz52 ..

Pyri di ne ' Aldrich Chemical Company ACS Reagent Srece ACS Rt?agent C r ~ l e

POCi Alfa Inorganics, Ventron Corp. Puri t y U ~ % ~ G W

lnlilshi re Chemical Company

DMF Fisher Sc ien t i f i c ACS ReagenL Grz& i-1 Cl Mal 1 i nckrodt

A1 1 i ed Chemi cal

Water Pantex Deionized

Analy ti ca 1 Reagz:;t ACS Reagent Grc&

111. Equipmclnt

The equipment layout is shown i n F i g . 1.

A. P r i mary- React i on Ves s e7 1

The primary reaction vesse l was a Dow Corning 200-l i ter glass rc6ct,-.Gr-

vessel w i t h condenser and variable speed ag i t a to r .

supplied by e i t h e r a quartz heating mantel or a special I ~ ~ E T S ; C ~ CG7-i

' The he2.t car: be

inside the reactor. Hot o r l d water or steam can be c i r

t h r o u g h the co i l .

B. Hydrochloric Acid Bath Vessel

The vessel used f o r the HC1 bath i s a Pfsudler glass ! :ma szek:-

jacketed 200-gall on reactor with an af r-driven a g i t a t o r . ::-,e T

i s equipped with a Corning glass condenser.

C . . Fi 1 t r a t i o n

F i l t r a t ion was done in two U.S, Stoneware ceramic f i l t e r s . 'JZCULTT: t::s

supplied w i t h a watep sealed vacuum pump.

D. Drying

A 1 7 drying operations were done w i t h a Stokes vacuun she!f C:-jsr,

E o Mi s ce7 1 aneous

A l l valves on vessel d r a i n were Grenell-Saunders g l a s s - l i ned v ~ l ~ e s .

A l l t r ans fe r hoses wkre Teflon l ined.

-6-

IV. Calculated Temperatures of Reactions

The preparation of picryl chloride from picr ic acid involves Z F . - C ~ T Z ~ 215-

thermic reactions: (1) pyridinium p i c r a t e from p i c r i c acid z-+ .'.* - - r r -yJ - & ' * - , - * -..- 1

and ( 2 ) p i c r y l c h l o r i d e from t h e pyridinium picrate a d TCC1.. For tk.2.::

types o f chemjcal reactions, analytical techniques are beir ;g de;i+2;cijcd ",T.

order t o predict the temperature r i se o f the reacticn.

( o r estimates) are necessary i n order t o assure adequate react:on :E-:;~E-

ture control f o r a good yield and t o prevent dangerous operating corci:z;c~s

due t o excessive temperatures.

These arcc ic t ' c r s

A. P y r i d i n i um Picrate Reaction

For analysis , the p y r i d i n i u m picrate reaction has been z s s r ; ~ ~ < cc, 5

f i r s t -o rde r reaction with time since the pyridine solut ion 7s

in to the p ic r ic acid solution i n a short time period.

t i on , the concentration o f reactants can be assumed t o decay o r . p

nent ia l ly ( f i r s t -order type) versus time. The energy ba lan

presented as

For t h i s r2cc-

- 1 ... - I

UA (T-T ) i- p C P V ~ 6T = VK, C

where

U = overall heat t ransfer coeff ic ient

A = heat t ransfer area

T = batch temperature

T = coolant temperature

p = density o f batch

C, = spec i f ic heat o f batch

V = volume o f batch

K O = constant, energy o f reaction

3 =, reaction time constant

C

Integration of this equation (1) yields

...... A

- = L t-to

t o = i n i t i a l time

The equation (2 ) has been rearranged in to dimensionless grot;i;s a z c

plotted f o r various ra t ios of h /P i n F i g . 6 .

In order t o solve equation ( 2 ) , the constants, KO and A, GUS’; be

established from the heat of reaction and the time for ?;he ccnceczra-

t i o n o f reactants t o decay t o a l o w re la t ive ly steady-state i e v e ? ,

The heat of formation of pyridinium picra te is unknown so t n s t E

d i rec t balance could n o t be made. Therefore, the to t a l reaction has

been considered as a change i n bonds s imi la r t o those encountered ifi

the s o l u t i o n reactions o f the type NH3 + HCI + H,N:HCI.

of a number of these typical reactions indicated tha t the heat of

Consider&tion

reaction was usually near -12.5 Kcal/g-mole. T h i s va:ue V I ~ S tkerL i s e d

for the calculation o f KO.

Since the A constant f o r the decay is dependent on the mass dl ; f fus io!?

and reaction rates i n the batch, the equation ( 2 ) has beer, s s 1 e G ?G:

peak temperature f o r various values o f PT. (These pe&s 2 ~ l t ~ ~ x t i cz: : j

lead t o a spec i f ic r a t i o of A / P fo r each value o f PT.) R e s u l t s icr

- peak temperature versus t im are presented i n F i g . 7 and indi:zte c

r i s e of 10 t o 22°F i n the probable decay time z m e .

r 0

I - ) U ru L.

I - -

a)

'I- o -I-)

. .- +-J

L r - 'U > m

r- c -.

-3 c-- , <> :>

r - c

(i- o 4-J c

> v)

LZ I-

,- C 0

ru QJ II

.I-- 0 a

4 3 c (d c,

a _c -I-'

U 01 r?

rl- 0 L a

*r v) (L1 0 u

fl) E 0

- I - )

a. 3

c 0

s-, *r-

3 0 L

0 q-

S 0

+., ru 3 0- Q,

cu I: I-

+I-

C 0) aJ a

m a, L 3 s-, lu L aJ

a, 2-

v) C 0 u

V Id

t! S 0

c, 3

0 v)

aJ c, a L . u L1

*I-

v

.I-

e, L aJ U L

0 0 (d

a J a J L L a c , c c ( d o

n

h P c,

0 I 0 L

*r

*I- E v) r

aJ 3 0- a, v) c 0 V

aJ N

c, cn m u3 I

IC- 0

v) S 0 V h

0 a cn s o o r m u

I- 1

t-

c aJ S 0 a X aJ

aJ 53

rd > (d

W S ru

7 2 L a, c aJ

v) a

aJ x 4J

'4- 0

-3-

The coniparison of measured and calculated temperatures o f :?.e : e e ~ : - ~ s < - < as presented i n F ig . 8 indicate f a i r l y good agreement. i r *e 1-5 ,

pea.k temperature o f 96.5"F conpares we?l with the measured' v a i w cf

98.2"F. However, the theoretical time-to-complexion o f t r , ? rccct;cr;

of 16.5 minutes i s f a s t e r t h a n the n-easurcu value o f 22 ;.;:iLe?. ' ,

T h i s time difference may be due to a lag in the mass d1ffusicjr, a, 1s

indicated by the temperature, l a g a t the s t a r t o f the r u n . ( T h i s l a g

appears t o be about 5 minutes a t 90°F).

The heats of reaction for this picryl chloride reaction zr,d t h e

pyridinium picrate reaction as inferred from the t e s t resu;;s ere :-.

good agreement (within 6%) w i t h the assumed values. Tnls cos?ar;scn

indicates another important potential use o f the data i n conjkr .c t ;x

w i t h the analytical procedures t o determine the apparent h e a t sf

react? on.

Con dens e r

~ - .

1 ‘

Thermocouple We1 7

pecial Submrged 007 ing-Heating Coi Is

200 L i t e r Reaction U n i t

Fig. 1

-r 7 - .-.? c)

c) J

L C

*r

,

e-

m LL

1.0 .

. 5

0

Fig. 6

Temperature Increase for Exothermic First-Order Reaction+!ell-Stirred, Batch Process

UP, . P T = ----(t-to) PCpV

? .

F i g . 8

- i 7 -

Temperature Rise f o r P i c r i c A c i d , - Picry l Chloride ExotherEfc ???ctSsr!

t . ,

. . . . . .

1 .

-' 99°F Asympto te - ,

I

- ,

90

Constant Reaction Rate - i enperature -

( O F )

80

-

- ! T (Cooling water)

c Average, Estimated

---------- --- (Cooling krater In le t )

1 701 i ;. Tco

> 1 I I t

20 30 40 50 0 16

Time (Minutes)