The first successful direct azocoupling of nitroaromatic anion-radical

THE PXt(ST SUCCESSFULDIRECT AZOCOUPLIHO OP IYXTROAROHATIC

TODRESZ.V.:

HOVSEPYAN G.TS.,

Neenayanov Institute

and IONINA YB.A.

of Orgkno-Element

Wepounds,

USSR Academy of Solencee, Vavllova

ul.

28, V-334 Moscow 117813 CSP-1,

USSR

(kcrfnd h UK23March 1988) l- o-Dilinftrobeasme dfartion reacts rith p-l,N-dfmet dnobeneenediatoniws cation, fadng 2-nltrop-41-XJi-di8et hz aminoaeobenzrne. a-Dinitrobenriene anion-radical, interacting with benrenedlatonium cations that contain N.N-dimeth~lrrino or nitro group in para-position, yield8 3-niiro-6&ydky-rli-Y.I-blPetLvlaminoa%o~nzene end 3.4’4lnitaw44udxvxYrcobanzexia, re8p&tively. The above compbnds ax?+'fond lri k&la promoting the sfability of ian pairs betrebn o-dinltrobenxene dirniow or anione-nrblcnls and poter&\ol catlolu. lfth the only the electmn-transfer reaction tiasociation of ion paire, products are obqorved.

Abetmat

o-Dinitrobentene (o-DNB) by itself ie incapable of entering Into the MOcoupling zwaction. This reaction haa been found to occur when o-DNB ie converted into anion-radfcal or dfanion forms. The interaction will proceed differently with depending on the substrate Ionic form. Used as the ritagent were dlazosalts the general foxmula: p-RC6H4N2BP4 (1, a RrYe21, b IbN02). R02In the caee of o-DNB dlanlon (2) Ipso-coupling occure followed by llfnsination 80 that o-nitroaeocompound (2) ie fonued, Scheme 1.

Reaotion 1 ir accomwled by the dianion oxidation followed by the fomtion of o-DNB, N2, and dimethylanillne. In TliF (E - 7.4) the nitm group lubetitution by the arylato group proceeds concumntly the redox ~ZDCWI~, rhereaa in H&R s199

(&I 36.5) only the redox reaction takes place, 08% Table 1. The above difference i% cau%ed, in our opinion, by the ion-pair stablli%ation in poorly diasocirtin& THP and their decay In the strongly dlesociatlng YeCI. slhen o-DXB anion radical potassium salt (~)reacta with ditto cation in DMSO(E- 49) only electron tram&w happen%. In THF, however, atououplfng oacura 0bew-d hem is not ipso-eubstitutfon,, ae in the c%ae of dianion (21, but the arylaso fnsgnent enter% in the p-position of t,h!, bensene ring. At the %%metime, the para-nltro g~pup is oonverted into a hydroxy g&p. This 1% accapsnied by the HO’ nrdioal lo%%; nitrogen monooxide was detected by tha &u ph884 IR analyei%. The observed eerie% of conversion% is shown in Scheme 2 snd ha% been confizxi-

ed by ahock experimente:

the exposure of salt (A) to air or *ator treatment didn’t lead to the replaa%nb& of substiate nitm group by the hydn>ry group nnd the addition of H2‘*O after the mixing of -agent% didn’t result in the labellld OH group

in produet (1). Ho changes associated with the presence of '80 ieoin the tops in the amount exceeding Its natural pewentage have. beon obeerved ma%%8pectns.

% -0’

p-t?C&,+N-N Tic

‘0’ Anion-radical both in azocoupling Interaction Reagent

(3) i interacting and in electron

of o-CNB anionic

Subetrate

(&a

R-Me&bR-NC&)

with diato cation% (1 2, &Is take& part transfer ma&ins (Table 1). Table 1

ronno with diazo

Solvent

cations

(equlmolar

Yield of products, o-DRR RV$ (R in brackets) 72 60 M’Me2) 83

R2 THP YeCN

THF THP THP + W-crowd:: THF + 18..crown-6

nwS0 DMSO

II, of theor. At0

compound 1

* 13 0

92

81

(Rlle2)

90

12 26** Be 94 91

13 27 95 93 83

(NO2) (XNe2) (NW21 (NO21 I

71 63 89 94

UWe2)

90

0

93

81 .

(N02)

95

0

l

1 I 2 Reagent : eubetrate, “NO w%e also found ***18-Ccorm-6 in equimoler quantity

ratio)

with reepeat

to (3)

2 a , 46’ 2 2 , w* 0

0

Dim

RedOXrmction product8

ia

and the

completely

the only

one in

products

8uppmsred

of

DYSO; in

atocoupllng

The differrnoe potassium their

bicyclic

to

structure

compound

is

resulted

Prom this azo

cation

the

rpin

with

density

lng

with

a

is

It

M

of power

the

the the

1.0.

TRP only

8alt

We have

by the

replacement

(A) by the

mO8OmOX’iC

the

(6)

of

salt

in

of

bi-

(6).

salt

on which

(6)

is

qo8t

of

to nitrobentene

(6)

and (1)

tran8fer

THP by DM!30 not

gmpS* route

cation

8alts

COITeOpnd-

potaseiun g1~up8,

in

suoh aromatic

the

18 elmllar

found

with where88

8tNCtUIW

two nitro

potassium

two nitro

the

diiierenoe

(2 fi)‘,

to ascertain

one-electron

of

coupled

anion-radical

one of

(I).

(2)

ahd

also in

a8 well.

8tNotUlP

o?

interest

p-nitrobenzene

salt

n

18

substitution

The fosuation

po881ble2).

at only

in

(even

transfer

Therefom,

be caused

ortho-arrangement

concentrated,

compound8 place),

ie

low lonltlng

potaaelum

take8

‘) the

electron

Asoooupling

h88 a quinoid

aX3matiCity

view,

be coordinated

anion-radical aromatic

of

interrctlon

to

(f

from

point

In media known’

it8

the

8eem8 to

(1)

of

addition.

of substnter

MULiOn

NtsiM

yield8

compamble.

ether

prevents

Sahemes 1 and 2).

structure. (3)

decay

reactivity

the

(see

electrotia

anion-radical ing

in

oatlone

am

5mo1

anion-rabl

TRF the

in THP by 18-crown-6

or xwactlon 2, the ion pair

can.

ofrliworronlalic

-up&ing

to

route

chrnging

reaot

(no

the

with

aeocoupl-

reaction

direction. The ?ir8t

suoceseful

accompll8hed. should

Po88lble

be considemd.

o-DNB Immediately (wlthout the

of

mixture group

the the

diaconlum

The reaction o? 2,

or

para)

dlaceni~

vent

ewe,

azenium tale

are

hydrogen

?or

the the

not

lsomerio

with to

seem

with

be obtained.

radical

from

the

volume).

eubetrnte,

(1) attack

Secondly,

it

from

one-electron

the

other

respect

to

Actually

the

only

Corpound 3 !iE

been

2,

on neutral to

the

reagent

18

the

re

-

reduction

molecule

be realized.

thw

to Scheme

sub8tmte

of

(4).

Otherwlee,

a

po8ltlon

of

one leomer

of

the

encounter A8 8een

radical

8ecood

Only

with

?m

type

upon the

famed

which

yield

is the

the

a particularly

emergence

other

experimental

transfoxmation

atom abstraction

implies

the

the

molecule dats

dinitrogen

solvent

(1)

(Table

correapondlng

iroar the

of

high

radioal and the

1),

the

ir

aso

produced

eliminntlon benzene

points

and elemental

Y.p.,

oc

(eolvent 132 (benreue)

Ref.

)

analy818

3

1%

of

the

sol-

leocoupling route

would of

when aryl

derivatives

dl-

radi-

after

the

molecule.

ra8ults

?or

General

aso

2

compound8

%% PO&

formula

stability

from

th8 main

Table Melting

h88

alternative

dlacenium

, re8ulting

doe8

anion-radio81

reaction,

transfer

radical

type

would

mdloal. it8

be poeelble.

is

for

cage

by the

first

this

3).

The reaction the

It

dlasenium

the

o?

electron

solvent

two acocompounde

(ortho

(Tables

the

cation

of

acocoupllng

Pimtly, aiter

leaving

combination o?

direct mechanisms

C

obtsined.

(Calculated) ii

N

C14H14N402

62.22

(62.22)

4.91

(5.18)

20.67

(20.75)

C,4P,4N40j

58.52

(58.74)

4.91

(4.89)

19.51

(19.5s)

49’.86

(50.00)

2.80

(2.77)

19.42.

(19.44)

(bentone) /b

‘i12 (bensene)

4

Cl PHeN4OS

5202

Table Spoatxxl Compound.

Xaea epeotrum

ohaxwtorlstlce (m/r)

of 680 compoundr obtalaed

270 Y+,

1150 (I (C-N),

143 (Y-c~H,IZ~~)+,

1372 E @O,,,

aminoato-

t 20

(

z

(S,

p.p.m.)

cm-l)

2-IOitrQ4’-P,Pdimeth.@-

&-c6ii4ilB20-192)+

PMRspectrum

IR 8pectruP

(3’)

benzene

3

7.95-7.55

m ,(4H; C6E4g02),

7.81

(211 H2-H6, J 9 HE)

1540 m (E022,

6.86

(2H: H3’-n5:

1610 e (N-B)

3.12

(6H, EYe2).

10.62

,

J

)

3-Eiitro-4-

286 X+,

1145 e

hydmxy4’-11,13&i-

128 (m~6~3(~)Mo2)+

1170 D (C-8).

8.50

d (1Ht H? Jpd

120 (M-c61I3(0rr,no,-%,:

1320 6

8.12

dd (?H, I@,,

7.87

(2H, H2k6;

larthyl-

1360

8minoMo-

benzene (I E) 3 ,r’-Dinitro-4hydmxyacobenz*ne (1 b)

9 Ifs)*l

l

and

and (N021s,

2.5 ILL)*

J 9 Es) .

1530 m (R02&,,

7.37 d (la,

1605

(N-g)

6.87

(2H, H3:H5: J 9 Xs).

and

8.74

d (18,

l

288 M’,

1320 a

166 (Y-c6H41102)+,

1342 e (Y02)g

, 0.47

-0

1540 m (HO,),

8.34

fY-C6H3(@!)~02)+,

e (1X, OH),

138 (Y-C6H3102-H2)+, 1628 e (B-N) 122 (M-C6H3(OH)N02-N2)+

H5, Js6

9 He),

H2, J2-6 2.5 Hs),

(2H, H31-H5; J 9 HE) 9 dd (lH,

X6,,

0.16 (2H, H2t-86: 3 9 HE), 7.45 d (lH, H5, JsA 9 Rt).

Thus, the reaotion, having no enaloguee, of the atocoupling of o-DlfB preconretied into the anion-radiaal fonr has been found. Aacompllrhed on model8 this reaction oan in all probability be applied to mom complex ayeteme aa wall, In partioular, in the synthesle of teuhnlcally valuable dyes.

ChromrtoRzuphic determinations WOPBperfonaed on Chzvm chromatogmph-4 (carrirr gae nitrogen, eta.inl.88 stool column 3 x 3700 = with Carbowu 20 M on elleniced ohmmatone N-All, 40-60 mesh) or on Tavet-101 chromrrtograph (carrier gu nitrogen, glass column 3 x 2000 PIED with 5 % Sg-20 on chnaurtone II-AU-DMCS 60-80 meeh) . YaRnstIc ru8oeptibilitg wne m~asursd on ma@Ietio balance by the mrthod at ~1%~ end 20° and field latenaltles from 500 to 3500 01.

Faraday

Yue epectxw wexm obtained on AR]: MS-30 instrument rith IS-50 automatlo data collection system at ionlertion voltege of 70 V. The syetur of direct inroduction OS lemple into the Ion source me heated to a ternpenrtum not lxoeeding the m.p. of the investigated compound.

IR 8DWtl-8 (oompactod rlrturr ry

Or

iOM

In awn,

was collected

soprmtion

in

The eub8tmte

aa the

obtained

o-dlnitrobencene

(o-DNB)

theor.)

2.06

solid

salt

em

there

are no characterletlc

1420

contains

reg.iOM,

cm-’

(cf

wa8

ed with

air

of

THF.

The compounds oi

tion

cm”,

tate,

the

1%0

jr1

TRF.

ror

‘13?

Pound,

Prop

cyclooctain 5.

small g

(2)

(yield

salt

abeorptlon

solid in

1060,

1200,

of

data,

ealt

bande

at

ar-

1.68

susceptibility In the

the

IR-speot-

the

the initial of

in

Table -30°

in

particles

1330

and

7390

and

malt

(A), salt

ealts

of

with sealed

for

liquid

, and the

hexane

of

the

diaconium

used

lnmtead

flask

filled

After the

ether

substances

of

gae-phase (absorp-

solution

separated

with

5).

corrempond-

monooxlde

(GIL),

residue

of

the

1 hour.

or nitrogen

aa RC61$ in

treat-

(92-95

salts

dry

or DHSO raa

there

sample

this

ensued

dinso

a thoroughly

a mixture

in

with

THP wan mixed

kept

solid

In DMSO we=

recovery

potassium

analysis)

the

solution

o-Drib

1) Y&B

and then

gel,

of

nitrocompoundr

50 ml of

at

potassium

analysis

THF or itr

The characteristics

p-dinltrobenzene boron

(0.01 ror

at

-30°

on

wan a

or ethyl

ace-

obtained

are

glven

roll

Al24 ’ 0~ %(t

anion-radical

or

rreshly

10 min with

latter

and 0.72

- ethyl

and orystals C 63.%

0.35

with H 4.88

in

The reaction filtered

g (57 I)

salt

with

(6)

of

30 ml or THP (0.01

mol)

mixture A red

out

In 20 ml

wm etimd

solution

to give

0.89

over

153O (ethyl

KBP4 (IR and lumlnoecent

I 11.50.

alcohol)’

C13H12”203*

were

a

g ( 40 % )

4-nitro-l’-aethoxy-N,I-diphenylamine,

m.p.

was

the residue (Iseparated on a thin 2rl). 0.92 g of p-dlnltmbenxene ,

acetate, g of

(6)

to waxm up to 25O.

, the

wan evaporated,

(hexane

salt

or YeOC6H4N2BP4

evolved.

allowed

compound

prepared

8u8pensior (55 I)

and then

potassium

fluoride

wae obtained

dlato

or an~sole,

2’2’3

vacua.

dipotaasium

paremagn et10

in

(Bee

123 cm3 or nitmgen

or g

to

of

am well

(silica

of

precipitate

layor

undrr

o-DEB anion-radical

wae evaporated

analyees) . The riltlrte 0.16

with

described

3.

-30°

or unnaotod

of

(volumetric

cr.7),

a8 eluent). 2,

10 Pin

dark

internal

rllter

wetic

observed

or dianion

pmaeum,

column

Suspenalon or

in

particlea. group

foxme

mol)

paethoxyphenyldiaconiun

at

prelimina-

InBtMent,

procadure

on a glass

the

am

water

nitrogen

Interaction

mlxod

to

bands

content

ionlo

The rlltrate

Tables

Iraotion

the

after

or dlanion

o-DNB dlanlon

su8penelon

were mlxed

at nom1

22 x 600 =

WP-200

TRF and dried

nitro

g

In come caeea

detexmlnation

in

(3)

(0.01

rluoride.

riltored.

of

anion-radical

nitrooompound

at

cold

According

the

of

boron

argon

2.17

or air-frwo

Suspension

with

wllete

-700.

by the

orr

According

wae obtained.

Intemctlon lng

o-MB

When edt

dry

donor

rilteend

intense

susceptibility

95%.

Wr over

KBr window*

anion-radical

no paramngnetic

but

g of

theor.,

magnet10

at

in

folard

6).

Prom 1.68 95 % or

Into

g

was obtained.

cm-’

with

on Btier

electron

with

the 1530

recorded

were

uamhed twice

preeeurw,

% $ or

rilter

pbaeo

(CD3J2C0.

used

The precipitates gone

with

a glue

iMtMent

ga8eoun

ouvette

wan converted

tetraenepotassium

the

an lvaouated

25O) were

(at

TMS, solvent

UR-20

011

soanning);

In a trap

PYR lpeotrr etandard

obtalned

U@CI

iaat

5203

azocoupliagof fliWoWxnaLic anioo-radical

Dim

obtalned.

sm

2. V. Tcxmm

Caloulatrd,

I:

C 63.93

Mnna rpeotnu

(m/s):

H 4.92 244 Y+, 182

PUR spectNmr

(&,

I 229 4.10

(Y-CH )+,

am-‘jr

+3 .

# (3 P,

7-8.5

IR epectxum (3,

1325

l

al.

11.47.

(Y-Cii20-2(O))

p.p.n.)r

cl

(Y-CR20)+,

OCH3),

6.42

I (1 H, XH),

m (8 H, 2 C6H,).

(R02)8,

1520 8 (R02)a,

anion-radical

Iatrlrotio8 of nitmbencomr

214

potaseium

3330

l

(IQi).

salt (1, with

p-rrthox~husldlasonium boron fluoride Surpr~lon of 0.01 mol (2.22 g) of YoOC~H,~~~B?~In 20 ml of TH? was added during

10 mln under

prepared

salt

(1)

lnten8ive

rtlrring

In 30 ml of

In DMSO tha

eue

from

-40

the

qspearlon

of

0.01

no1

subatmcos

to

are

25O for

of

freshly

roxw

stor-

Vigorous nitrogen evolution (210-215 om3 or 95 %) WM observed, the nixture turned dark red, and a yollorlsh drpoalt preolpltatrd (KBF), ylold 96 a). The filtrate wan evaporated, thr residue separated on a 22 x 600 ppll alllca gel ooluq (hoxano - ethyl aoetate. 1.17 g (95 %) of nltrobratone and 0.97 g (90 %) of anlcole worn obtalnrd. 311). ld at

tampexmturer

to

TRP; In other experiments the mixtures 20 min.

obtained

(anltole

yield

drops

to 80 %I.

1.

I.Q. Chambon and R.N. Adams, J. Blectroanal. Chen. 4, 400 (1%5); JJ, 825 (l%O). A.H. H&l and D.H. Cesko, J. Chem. Phya.

2.

C.Y.

Llng

R.L.

Ward,

3. 4. 5. 6. 7.

8.

mdlCendol1, J.

Z.V.

Todrom,

S.R.

Chakmbarty

Amer.

&as.

J.

Cham. Phya.

Chem. Sot.

Chrm. Rev.

a, u,

41, 12%

1099

3475

(1%7);

(l%l); (1974).

and S. Dulls, J. Indian Chem. 900. 2, 555 (1928). J.Th. liowlttand H.V. Mltohell, J. Chum. Sot. g, 225 (1905). Icv. AN SSSR, Ser. khlm. 1749 (1970); 2.V. Todxw, 631 (1980). Z.V. Todreo, &se. J. Phys. (3.0. 2, E.S. Llplna, I.D. Stepanov, I.L. Bagal, R.I. Bodlna,and V.V Poawkalln, ZhOrKh l&, 2404 (IWO). of Ralrlag the B.I. Buryak, Yu.P. Koval',and T.P. Kudlnovs, In “Pmblma Kiev, p. 80 (1984) (In Russian); AccuImoy or cu AMlys18 YlMurmellta”, Referatlvnyl Zhuraal “Khimiaw 15 0 179 (1985). K. Hlrauchi and T. Amano, Chem. Phann. Bull. a, Il.‘0 (1970).