Reactions of N-(Pentafluorophenyl)carbonimidoyl dichloride with fluorinated benzenes in the presence of AlCl3

Article abstract of DOI:10.1135/cccc20021449

N-(Pentafluorophenyl)carbonimidoyl dichloride (1) reacts, in the presence of excess AlCl₃, with fluorinated benzenes containing 1-5 fluorine atoms in the molecule. With fluoro- and 1,3,5-trifluorobenzene the reaction gives the corresponding imi

Full text of DOI:10.1135/cccc20021449

N-(Pentafluorophenyl)carbonimidoyl Dichloride
1449
REACTIONS OF N-(PENTAFLUOROPHENYL)CARBONIMIDOYL
DICHLORIDE WITH FLUORINATED BENZENES
IN THE PRESENCE OF AlCl3
1,
2,
Tamara D. PETROVA *, Vyacheslav E. PLATONOV *, Leonid M. POKROVSKII,
Tatyana V. RYBALOVA and Yurii V. GATILOV
N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch,
Russian Academy of Sciences, 9 Lavrentyev Ave., Novosibirsk, 630090, Russia;
1
2
e-mail: petrova@nioch.nsc.ru; platonov@nioch.nsc.ru
Received April 10, 2002
Accepted July 29, 2002
Dedicated to the memory of Professor Miloš Hudlický.
N-(Pen tafluoroph en yl)carbon im idoyl dich loride (1) reacts, in th e presen ce of excess AlCl3,
with fluorin ated ben zen es con tain in g 1–5 fluorin e atom s in th e m olecule. With fluoro- an d
1,3,5-trifluoroben zen e th e reaction gives th e correspon din g im idoyl ch lorides an d azo-
m eth in es; at elevated tem peratures, azom eth in es are form ed in in creased am oun ts. With
1,2,4,5-tetrafluoroben zen e an d pen tafluoroben zen e, in tram olecular cyclization , leadin g to
polyfluorin ated 1,2,3,4-tetrah ydroquin azolin e-2,4-dion es 9 is preferred. Th e side reaction s
are fluorin e substitution with ch lorin e an d form ation of 1,3-bis(pen tafluoroph en yl)urea
(10).
Keyw ord s: Electroph ilic arom atic substitution s; Friedel–Crafts reaction ; AlCl3; Fluorin ated
ben zen es; Im idoyl ch lorides; Azom eth in es; In tram olecular cyclization ; 1,2,3,4-Tetrah ydro-
quin azolin e-2,4-dion es.
Previously, polyfluoroarom atic com poun ds with an im idoyl ch loride group
were sh own to be effective electroph ilic reagen ts capable of in teractin g
with arom atic com poun ds in th e presen ce of AlCl3 1–3. Th us reaction s with
arom atic am in es occur at th e am in o n itrogen an d lead to th e correspon d-
in g guan idin es1. Reaction with a n itrogen –carbon m ultiple bon d in aro-
m atic im idoyl ch lorides or n itriles is a cycloaddition process givin g five-
an d six-m em bered N-h eterocyclic derivatives2. Reaction s with ben zen e an d
alkylben zen es yield azom eth in es3. In order to expan d kn owledge of th e be-
h aviour of arom atic com poun ds with polyfluorin ated im idoyl ch loride de-
rivatives as electroph ilic reagen ts, it seem ed in terestin g to study th e
reaction s of low-basicity fluorin ated ben zen es in order to fin d th e n ew reg-
Collect. Czech. Chem. Commun. (Vol. 67) (2002)
doi:10.1135/cccc20021449

1450
Petrova et al.:
ularities an d syn th etic ran ge. In th e presen t paper, th e results of in vestiga-
tion of th e reaction s of N-(pen tafluoroph en yl)carbon im idoyl dich loride (1)
with fluorin ated ben zen es used as reagen ts an d solven ts an d con tain in g 1–5
fluorin e atom s in th e rin g (fluoroben zen e, 1,3,5-trifluoroben zen e, 1,2,4,5-
tetrafluoroben zen e an d pen tafluoroben zen e), occurrin g in th e presen ce of
AlCl3 are con sidered.
Reactions with Fluorobenzene
Carbon im idoyl dich loride 1 reacted with fluoroben zen e in th e presen ce of
a 2.5-fold m olar excess of AlCl3 at 20 °C, givin g a m ixture of isom eric
im idoyl ch lorides 2. A con siderable am oun t of th e startin g dich loride 1 was
un ch an ged (th e ratio of 1 : 2 is 1 : 1.3, 19F NMR data). At 80 °C, th e startin g
dich loride reacted com pletely, but th e reaction m ixture con tain ed azo-
m eth in es 3 alon g with im idoyl ch lorides 2 (Sch em e 1).
F
F
F
N
F
1
CCl2
Cl
C
N
N
C
C6H5F
AlCl3
+
F
2
3
F
2a, 4-FC6H4
2b, 2-FC6H4
3a, 4-FC6H4 trans, 4'-FC6H4 cis
3b, 4-FC6H4 trans, 2'-FC6H4 cis
SCHEME 1
Accordin g to 19F NMR data, at 80 °C (12 h ) th e ratio of 2 : 3 was 3.6 : 1.
At 120 °C (17 h ), th e sole reaction products were azom eth in es 3.
As in dicated by GC/MS, im idoyl ch lorides 2 were obtain ed as a m ixture
of th ree (2a–2c) or two (2a, 2b) isom ers con tain in g m ain ly 2a. In th e reac-
tion m ixture obtain ed at 20 °C, isom er 2a prevailed (≈40%), th e am oun t of
2b ran ged from 1 to 3%, an d th e con ten t of 2c was less th an 1%. In th e 19F
1
1
an d H NMR spectra of th e isom er m ixture of 2a–2c, th e 19F an d H sign als
of 2b an d 2c virtually do n ot appear because of th e low con ten ts of th ese
isom ers in th e m ixture. Th e 19F NMR spectrum of 2a sh owed th e sign als of
th e fluorin e atom s of th e C6F5 group as well as th e m ultiplet of th e fluorin e
atom of th e ben zen e rin g bon ded to th e carbon atom of th e N=C bon d
(C-ben zen e rin g). Th e values of F-H spin -spin couplin g con stan ts observed
for th e latter sign al suggest th at th e fluorin e atom is in position 4. Th is is
1
1
con firm ed by H NMR data. Th e H NMR spectrum con tain s two equally in -
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

N-(Pentafluorophenyl)carbonimidoyl Dichloride
1451
ten se sign als, wh ose fin e structure suggests th at th e arom atic h ydrogen s are
in th e 2,6 an d 3,5 position s of th e C-ben zen e rin g. Th us th e m ajor isom er
2a is 4-fluoro-N-(pen tafluoroph en yl)ben zim idoyl ch loride. It can be as-
sum ed th at com poun d 2a is in Z con figuration sin ce th is is th e m ost typi-
cal form of arom atic im idoyl ch lorides3,4. Based on th e data on th e
orien tation of fluoroben zen e (para > orth o > m eta)5 in electroph ilic reac-
tion s, in cludin g Friedel–Crafts reaction s5,6, an d m ass-spectral data on frag-
m en tation of com poun ds 2a–2c, it was in ferred th at 2b is an isom er with
fluorin e in position 2 an d 2c in position 3.
Th e m ixture of azom eth in e products 3 con sists of th ree isom ers (3a–3c),
am on g wh ich 3a always prevails. We were un able to isolate th e in dividual
isom ers in an alytically pure form , probably because of th e sim ilarity of
th eir ph ysical properties. Th e 19F NMR spectrum of 3a sh ows th e sign als of
th e C6F5 fluorin e atom s as well as two equally in ten se sign als of th e
C-ben zen e fluorin e atom s, wh ose fin e structure is sim ilar to th at of th e flu-
orin e sign al of th e fluoroben zen e rin g of 2a. Th is gives us groun ds to be-
lieve th at th ese fluorin e atom s occupy th e sam e (4,4′) position in th e two
C-ben zen e rin gs. For on e of th ese sign als, th e ch em ical sh ift is close to th e
correspon din g value for th e C-ben zen e fluorin e atom of 2a, an d th e sign al
m igh t be assign ed to th e fluorin e atom in position 4 of th e C-ben zen e rin g
wh ich is tran s to th e C6F5 group. Regretfully, th e structure of 3a can n ot be
1
un am biguously in ferred from 1H NMR data, sin ce th e H sign als of th e two
C-ben zen e rin gs partly overlap. Th e spectrum con sists of two m ultiplets
with th e in ten sity ratio 2 : 6. Th e on ly assum ption th at can be m ade based
on th ese data is th at th e two proton s of th e tran s-ben zen e rin g, like th e
proton s in 2a, correspon d to th e m ultiplet sign al with in ten sity 2 (H-2,6)
an d th at th e sign al of th e oth er two proton s virtually coin cides with th e
sign al of four proton s of th e cis-ben zen e rin g. Neverth eless, based on th e
NMR data we ascribed to com poun d 3a th e structure of bis(4-fluoroph en yl)
keton e N-(pen tafluoroph en yl)im in e, wh ich was con firm ed by X-ray struc-
ture an alysis data.
In th e 19F NMR spectrum of isom er 3b, th e sign als of th e C6F5 fluorin e at-
om s are down field as com pared with 3a. On e of th e sign als of th e
C-ben zen e fluorin e atom s coin cides in its ch em ical sh ift with th e an alogous
sign al in 3a; th erefore it m ay belon g to th e fluorin e atom in position 4 of
th e tran s-C-ben zen e rin g. Poor resolution of th e sign al of th e fluorin e atom
1
in th e oth er C-ben zen e rin g an d lack of H NMR data for pure isom er 3b
m ade it im possible to un am biguously establish th e structure of azom eth in e
3b. X-Ray structure an alysis data, h owever, in dicate th at 3b is (2-fluoro-
ph en yl) (4-fluoroph en yl) keton e N-(pen tafluoroph en yl)im in e. Note th at
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

1452
Petrova et al.:
X-ray structure an alysis was perform ed for a 1 : 1.1 m ixture of 3b an d 3a
(19F NMR) because th e in dividual isom er 3b was n ot isolated. Th e data ob-
tain ed for both 3b an d 3a con firm th e above assum ption about th e tran s-
position of th e N-(pen tafluoroben zen e) rin g bon ded to th e n itrogen atom
of th e N=C bon d an d th e C-ben zen e rin g with a fluorin e atom in position
4. Th e structure of th e m in or isom er 3c was n ot elucidated.
Reactions with 1,3,5-Trifluorobenzene
Th e reaction of 1 with 1,3,5-trifluoroben zen e in th e presen ce of AlCl3 at
50–60 °C (17 h ) was in sign ifican t; it left a large am oun t of un ch an ged start-
in g dich loride 1 an d led to im idoyl ch loride 4 an d azom eth in e 5, th e for-
m er bein g predom in an t. Accordin g to 19F NMR data, th e ratio of 1 : 4 an d
of 4 : 5 was 5 : 1. At elevated tem perature (85 °C, 17 h ), m ore im idoyl ch lo-
ride 4 an d azom eth in e 5 were form ed (1 : 1, 19F NMR), an d th e startin g
com poun d 1 was foun d on ly in trace am oun ts (Sch em e 2).
F
F
F
F
N
F
1
CCl2
Cl
C
F
F
N
F
F
F
N C
1,3,5-F3C6H3
AlCl3
C6F5NHCOC6H2F3
+
+
F
6
F
4
5
SCHEME 2
Accordin g to GC/MS data, th e reaction m ixture also con tain ed a sm all
am oun t of 2,4,6-trifluoro-N-(pen tafluoroph en yl)ben zam ide (6), wh ich m ay
be result of th e h ydrolysis of im idoyl ch loride 4. An attem pt to obtain a
predom in an t am oun t of im idoyl ch loride 4 un der th e above con dition s by
takin g 1,3,5-trifluoroben zen e in an equim olar am oun t (but n ot in excess)
also afforded a m ixture of im idoyl ch loride 4 an d azom eth in e 5 alon g with
a large am oun t of un ch an ged startin g dich loride 1 (4 : 1 : 3.4, 19F NMR).
Wh en th e reaction was carried out with an excess of trifluoroben zen e, as
m en tion ed above, but at 120 °C (22 h ), th e m ajor reaction product was
azom eth in e 5 (th e ratio of 4 : 5 is 1 : 3, 19F NMR), an d th e con ten t of am ide
6 in th e reaction m ixture was but a few per cen t. At 170 °C (18 h ), on ly
azom eth in e 5 is produced. Th e an alytical an d spectral data for com poun ds
4 an d 5 com pletely agree with th e structures of 2,4,6-trifluoro-N-(pen ta-
fluorophenyl)benzim idoyl chloride (4) and bis(2,4,6-trifluorophenyl) keton e
N-(pen tafluoroph en yl)im in e (5).
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

N-(Pentafluorophenyl)carbonimidoyl Dichloride
1453
Reactions with 1,2,4,5-Tetrafluorobenzene
Heatin g 1 an d AlCl3 with 1,2,4,5-tetrafluoroben zen e at 170 °C (31 h ) led to
a com plex m ixture of products. Approxim ately on e th ird of th e m ixture
was th e startin g tetrafluoroben zen e; dich loride 1 was presen t in trace
am oun ts (GC/MS). Th e oth er products iden tified by GC/MS were
2,3,5,6-tetrafluoro-N-(pen tafluoroph en yl)ben zim idoyl ch loride (7) (≈1%)
and 2,3,5,6-tetrafluoro-N-(pentafluorophenyl)benzamide (8) (≈5%) (Scheme 3).
Th e expected azom eth in e was absen t. An oth er on e th ird of th e m ixture was
con sisted of th e h alogen derivatives of 1,3-bis(pen tafluoroph en yl)-
1,2,3,4-tetrah ydroquin azolin e-2,4-dion e 9, am on g wh ich th e m ajor prod-
ucts were 5-ch loro-6,8-difluoro-1,3-bis(pen tafluoroph en yl)-1,2,3,4-tetra-
h ydroquin azolin e-2,4-dion e (9a) an d th e isom eric 7-ch loro-6,8-difluoro-
1,3-bis(pen tafluoroph en yl)-1,2,3,4-tetrah ydroquin azolin e-2,4-dion e (9b ).
GC/MS data in dicated th at th e reaction m ixture con tain ed trace am oun ts
of 5,6,8-trifluoro-1,3-bis(pen tafluoroph en yl)-1,2,3,4-tetrah ydroquin azolin e-
2,4-dion e an d derivatives of 1,2,3,4-tetrah ydroquin azolin e-2,4-dion es with
two h ydrogen atom s in th e m olecule.
F
F
F
F
N
F
1
Cl
R5
O
CCl2
R6
C6F5
O
N C
F
NHCO
H
1,2,4,5-F4C6H2
AlCl3
N
+
+
F
F
F
F
H
N
8
R8 C6F5
F
H
7
9
(C6F5NH)2CO
+
9a, R5 = Cl, R6 = R8 = F
9c, R5 = R6 = R8 = Cl
R5 = R6 = R8 = F
10
SCHEME 3
Th e reaction m ixture also con tain ed th e products of fluorin e exch an ge
for ch lorin e in th e startin g tetrafluoroben zen e an d im idoyl ch loride 7. Th e
19F NMR spectrum of th e reaction m ixture sh owed th e sign als of 1,3-bis-
(pen tafluoroph en yl)urea (10), decom posin g un der con dition s of GC/MS
an alysis in to pen tafluoroan ilin e an d pen tafluoroph en ylisocyan ate. Th e
product ratio can be determ in ed by 19F NMR on ly rough ly because m an y
sign als overlap: 0.5 : 1.1 : 0.6 : 0.1 : 1 for com poun ds 7, 8, 9a, 9b, an d 10.
Th e previously un kn own h eterocyclic derivatives 9a–9c were isolated from
th e reaction m ixture an d ch aracterized. Th eir structure was determ in ed by
h igh -resolution m ass spectrom etry an d also by 19F an d 1H NMR an d IR
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

1454
Petrova et al.:
spectroscopy. Th e m olecular weigh ts of 9a–9c as well as th eir elem en tal
com position s an d MS fragm en tation are con sisten t with th e suggested
structures. Th e 19F NMR spectrum of 9a con tain s two sets of sign als from
two pen tafluoroben zen e rin gs an d two equally in ten se sign als from th e flu-
orin e atom s of th e carbocycle rin g. Both sign als are doublets of doublets
with spin -spin couplin g con stan t J(F,F) = 5.2. Th is value of th e con stan t
rules out th e orth o position of th e fluorin e atom s, in dicatin g th at th ey are
probably in m eta position to each oth er (cf. ref.7). Th e down field sign al was
assign ed to th e fluorin e atom in position 6, with h ydrogen an d ch lorin e oc-
cupyin g th e orth o position ; th e upfield sign al was attributed to th e fluorin e
atom in position 8, with h ydrogen atom in th e orth o position . Th e secon d
con stan t of th e F-6 sign al seem s to be due to spin -spin couplin g of th is flu-
orin e atom with th e orth o proton in position 7. Th e secon d con stan t of th e
upfield F-8 sign al m ay also be due to spin -spin couplin g with th e n eigh bor-
1
in g proton H-7. Th e H NMR spectrum of 9a sh ows on e sign al with a dou-
blet of doublets structure, also agreein g with th e arran gem en t of h ydrogen
an d fluorin e atom s suggested for 9a.
In th e 19F NMR spectrum of isom er 9b, on e can also observe two sets of
sign als from th e two pen tafluoroph en yl groups an d two equally in ten se
down field sign als from th e two fluorin e atom s of th e carbocycle rin g of th e
h eterocyclic system . Th e ch em ical sh ifts of th ese sign als are close to th ose
of th e sign als of F-6 an d F-8 atom s of isom er 9a, suggestin g th at in 9b th ey
also belon g to F-6 an d F-8. On e sign al is a down field doublet of doublets,
wh ich m ay be assign ed to th e fluorin e atom in position 6 [J(6,5) an d J(6,8)].
Th e oth er is a broad sin glet assign ed to th e fluorin e atom in position 8. Th e
1H NMR spectrum of 9b supports th is assign m en t. It con tain s a doublet of
doublets with expected J(5,6) an d J(5,8) con stan ts. Th e down field position
of th is sign al com pared with th at of isom er 9a seem s to be a con sequen ce
of th e effect of th e n eigh borin g carbon yl group, th us supportin g th e struc-
ture suggested for 9b.
For th e trich loro derivative 9c, th e 19F NMR spectrum con tain s on ly th e
sign als of th e two pen tafluoroph en yl substituen ts, an d th e 1H NMR spec-
trum sh ows a sin glet for on e proton .
MS fragm en tation of h eterocyclic derivatives of type 9 con tain in g two
h ydrogen atom s does n ot perm it an un am biguous structural con clusion .
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

N-(Pentafluorophenyl)carbonimidoyl Dichloride
1455
Reactions with Pentafluorobenzene
Carbon im idoyl dich loride 1 does n ot react with pen tafluoroben zen e in th e
presen ce of excess AlCl3 at 80 °C. At 150 °C (6 h ), th e un ch an ged startin g
com poun ds still m ake th e bulk of th e reaction m ixture, but traces of th e
1,3-bis(polyfluoroph en yl) derivatives of 1,2,3,4-tetrah ydroquin azolin e-
2,4-dion e with differen t n um bers of fluorin e an d ch lorin e atom s are already
presen t. Moreover, m in or (several per cen t) quan tities of pen tafluoro-
an ilin e an d 2,3,4,5,6-pen tafluoro-N-(pen tafluoroph en yl)ben zim id oyl
ch loride (11) were iden tified in th e m ixture. At 170 °C (31 h ), th e un -
ch an ged startin g dich loride 1 is still foun d in th e reaction m ixture, but th e
m ajor product un der th ese con dition s was 5,7-dich loro-6,8-difluoro-
1,3-bis(pen tafluoroph en yl)-1,2,3,4-tetrah ydroquin azolin e-2,4-dion e (9d )
(Sch em e 4).
Cl
O
N
F
1
CCl2
F
C6F5
O
F
N
C6HF5
AlCl3
Cl
C6F5NHCOC6F5
10
+
+
+
N C
Cl
N
C6F5
F
C6F5
9d
12
11
SCHEME 4
Urea 10 was also form ed in a con siderable am oun t. Th e con ten t of
im idoyl ch loride 11 (iden tified by GC/MS alon e) ch an ged in sign ifican tly.
Pen tafluoroan ilin e was also presen t in th e m ixture alon g with
2,3,4,5,6-pen tafluoro-N-(pen tafluoroph en yl)ben zam ide (12). Th e ratio of
1 : 9d : 10 : 12 : pen tafluoroan ilin e was 2.6 : 6.2 : 3.8 : 1.25 : 1 (19F NMR).
Th e m ixture also con tain ed th e products of ch lorin e exch an ge for fluorin e
in th e startin g com poun ds an d products as well as ch lorin ation products
(GC/MS). Even h exach loroben zen e was iden tified in th e m ixture th ough in
trace am oun ts on ly.
Th e structure of com poun d 9d was determ in ed by elem en tal an alysis an d
spectroscopy an d con firm ed by X-ray structure an alysis.
RESULTS AND DISCUSSION
Th e results of th e presen t work in dicate th at th e path s of th e reaction s of
dich loride 1 with various fluoroben zen es in th e presen ce of excess AlCl3 de-
pen d on th e n um ber of fluorin e atom s in th e fluoroben zen e m olecule.
Wh en 1–3 fluorin e atom s are presen t (reaction s with fluoroben zen e an d
1,3,5-trifluoroben zen e), th e m ajor products are im idoyl ch lorides an d azo-
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

1456
Petrova et al.:
m eth in es resultin g from alken ylation s of fluoroben zen es (elevated reaction
tem perature prom otes form ation of azom eth in es). For fluoroben zen es with
four or m ore fluorin e atom s (1,2,4,5-tetrafluoroben zen e an d pen tafluoro-
ben zen e) th e dom in an t reaction is in tram olecular cyclization leadin g to
polyfluorin ated derivatives of 1,2,3,4-tetrah ydroquin azolin e-2,4-dion e. In
th is case, im idoyl ch lorides are form ed in sm all am oun ts, an d azom eth in es
are absen t in th e reaction m ixture. A possible sch em e of th ese tran sform a-
tion s is presen ted below (Sch em e 5).
Parts of th is sch em e are an alogous to th ose wh ich we publish ed previ-
ously for reaction s of 1 an d AlCl3 with alkylben zen es3 an d for cyclization s
with substrates con tain in g a n itrogen –carbon m ultiple bon d2.
Th e electroph ilic in term ediate 13 form ed in th e reaction of carbon -
im idoyl dich loride 1 with AlCl3 attacks fluorin ated ben zen e, givin g im idoyl
ch loride. Th e latter, in turn , is an alogously con verted by AlCl3 in to an oth er
electroph ilic in term ediate capable of reactin g with a secon d fluorin ated
ben zen e m olecule, form in g azom eth in e. Fluorin ated ben zen es with up to 3
fluorin e atom s seem to be sufficien tly poten t don ors to react with th e
electroph ilic in term ediate gen erated from 1 un der th e action of AlCl3. In
polyfluorin ated ben zen e, th e electron -acceptin g ability of th e arom atic rin g
in creases, an d th eir reactivity with electroph ilic agen ts decreases8. More-
over, on e can expect th at ion isation of th e C–Cl bon d in im idoyl ch lorides
7 an d 11 also decreases to som e exten t because of in creasin g destabilization
of th e positive ch arge th at appears on carbon un der th e action of AlCl3.
Th ese factors are probably respon sible for th e fact th at in th e case of
1,2,4,5-tetrafluoroben zen e an d pen tafluoroben zen e in term ediate 13 in ter-
acts with th e n itrogen –carbon double bon d of th e im idoyl ch loride with
subsequen t in tram olecular cyclization to 1,2,3,4-tetrah ydroquin azolin e-
2,4-dion es 9. It is n oteworth y th at in term ediate 14 is a ben zyl type
carbocation in wh ich th e para- an d orth o-fluorin e atom s m ay be replaced
by ch lorin e un der th e action of AlCl4– (cf. ref.9) so th at th e cyclization step
m ay in volve an attack of th e n ucleoph ilic cen ter on th e positively ch arged
carbon bon ded to both th e fluorin e atom (=C+–F) an d th e ch lorin e atom
(=C+–Cl). Possible path s to com poun ds 9a an d 9d are sch em atically repre-
sen ted (Sch em e 5) by in cludin g th e con tribution s from reson an ce struc-
tures 16 an d 17.
Isom er 9b con tain in g a h ydrogen atom in position 5 is probably form ed
accordin g to a sch em e an alogous to Sch em e 5, but th e reaction in volves
isom eric 1,2,3,4-tetrafluoroben zen e. In deed, an alysis of th e 1,2,4,5-tetra-
fluoroben zen e used for th e reaction in dicated th at th e startin g m aterial
con tain ed about 97% of th e com poun d an d approxim ately 2% of
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

N-(Pentafluorophenyl)carbonimidoyl Dichloride
1457
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

1458
Petrova et al.:
1,2,3,4-tetrafluoroben zen e im purity, wh ich led to com poun d 9b. Th e for-
m ation of h eterocyclic derivative 9b, in turn , suggests th at un der th e given
con dition s isom eric tetrafluoroben zen es m ay beh ave an alogously to
1,2,4,5-tetrafluoroben zen e.
Sch em e 5 was supported by form ation of h eterocyclic com poun d 9d as
th e m ajor product in th e reaction occurrin g on h eatin g (in a separate run )
of carbon im idoyl dich loride 1 with th e auth en tic im idoyl ch loride 11 in
th e presen ce of excess AlCl3 (Sch em e 6).
Cl
O
F
N
F
1
CCl2
F
C6F5
O
Cl
N C
AlCl3
N
+
C6F5
Cl
N
F
C6F5
11
9d
SCHEME 6
At elevated tem peratures, side reaction s are prom oted. Th ese are prim ar-
ily processes of ch lorin e exch an ge for fluorin e. Th ese processes in sub-
strates, leadin g to products wh ich m ay be in volved in th e tran sform ation s,
an d an alogous processes with th e en d products com plicate th e com position
of th e reaction m ixtures an d th e gen eral picture of tran sform ation s. Th us
ch lorin e atom s m ay appear in com poun d 9a as a result of th e side reaction
of ch lorin e exch an ge for fluorin e in th e in itially form ed 5,6,8-trifluoro-
1,3-bis(pen tafluoroph en yl)-1,2,3.4-tetrah ydroquin azolin e-2,4-dion e, iden ti-
fied in trace am oun ts in th e reaction m ixture obtain ed in th e experim en t
with 1,2,4,5-tetrafluoroben zen e. On th e oth er h an d, ch lorin e atom s m ay
appear as a result of th e reaction of 1 an d AlCl3 with th e products of ch lo-
rin e exch an ge for fluorin e in th e startin g tetrafluoroben zen e, wh ich were
also iden tified in th e reaction m ixture. Th e sam e h olds for com poun d 9c.
Oth er side reaction s also occur in th e presen ce of AlCl3 at h igh tem pera-
tures. On e of th ese processes leads to urea 10. Th e reaction path leadin g to
10 is n ot quite apparen t, but it seem s to be th e con sequen ce of th e tran sfor-
m ation s in volvin g th e products of h ydrolysis of 1 by air m oisture. On e of
th ese products, pen tafluoroan ilin e, was recorded in reaction m ixtures by
19F NMR. For 1,2,4,5-tetrafluoroben zen e an d pen tafluoroben zen e possess-
in g low reactivity, th e con tribution from th e reaction s with pen tafluoro-
an ilin e is com parable with th e con tribution s from oth er tran sform ation s
an d h en ce th e con ten t of urea 10 is reason ably h igh . Th e low reactivity of
th ese fluoroben zen es an d th e h igh con ten t of tar products lead to low
yields of m ajor products.
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

N-(Pentafluorophenyl)carbonimidoyl Dichloride
1459
EXPERIMENTAL
19F an d 1H NMR spectra were recorded on a Bruker WP-200-SY in strum en t with h exafluoro-
ben zen e (162.9 ppm from CCl3F) an d h exam eth yldisiloxan e (0.04 ppm from TMS) as in ter-
n al stan dards an d CCl4 as a solven t. IR spectra were m easured on
a Specord M-80
in strum en t for 5% CCl4 solution s. GC/MS an alyses of th e reaction m ixtures were perform ed
on a Hewlett–Packard G 1081A system wh ich con sisted of an HP 5890 (series II) gas
ch rom atograph an d an HP 5971 m ass selective detector (EI 70 eV). Capillary colum n
HP-5MS (5% diph en yl- an d 95% dim eth ylpolysiloxan e): 30 m × 0.25 m m × 0.25 µm . Carrier
gas h elium , 1 m l/m in . Colum n tem perature elevation m ode: 50 °C for 2 m in , 10 °C/m in ,
280 °C for 5 m in ; evaporator tem perature 280 °C an d ion source tem perature 170 °C. Th e
data were collected at a rate of 1.2 scan /s, m ass region 30–650 am u. Th e GC/MS data are
given with out correction an d h en ce th ey are approxim ate. Colum n ch rom atograph y was
carried out on silica gel (140–315 m esh ). Th e m olecular weigh ts an d m olecular form ulae
were determ in ed m ass-spectrom etrically on a Fin n igan -MAT-8200 h igh -resolution in stru-
m en t (n om in al ion izin g electron en ergy 70 eV). Petroleum eth er (b.p. 70–100 °C) was used
as on e of th e solven ts. Auth en tic im idoyl ch loride 11 was prepared by a kn own procedure10
.
MS an d IR data are given in Table I; NMR data of am ides, im idoyl ch lorides, an d
azom eth in es are listed in Table II; NMR data for 1,2,3,4-tetrah ydroquin azolin e-2,4-dion es are
presen ted in Table III.
Reaction s of 1 with Fluorin ated Ben zen es in th e Presen ce of AlCl3
A m ixture of com poun d 1, fresh ly sublim ated AlCl3, an d excess of fluorin ated ben zen e was
h eated in a flask equipped with a stirrer an d a reflux con den ser with a calcium ch loride tube
or in a sealed glass am poule at an appropriate bath tem perature. Th e reaction m ixture was
cooled an d th en decom posed with cold water (100 m l), extracted with eth er (100 m l), th e
extract was wash ed with water to n eutral pH an d dried over an h ydrous CaCl2. Th e solven t
was distilled off till th e precipitate started to settle, an d th e eth er solution was an alyzed by
19F NMR an d GC/MS.
Reactions with Fluorobenzene
Th e reaction s of com poun d 1 (0.26 g, 1 m m ol), AlCl3 (0.34 g, 2.5 m m ol) an d fluoroben zen e
(1 g, 12.8 m m ol) were carried out at room tem perature (22.5 h ) an d at 80 °C (12 h ) in a
flask equipped with a stirrer an d a reflux con den ser with a calcium ch loride tube. Th e reac-
tion m ixture obtain ed at 80 °C (19.5 h ) from com poun d 1 (0.78 g, 3 m m ol), fresh ly subli-
m ated AlCl3 (1.02 g, 7.5 m m ol) an d fluoroben zen e (3 g, 38.4 m m ol) con tain ed com poun ds
2 an d 3 in th e ratio 2 : 1.5 (19F NMR). Accordin g to 19F NMR data, th e ratio of 3a an d 3b was
1 : 0.4. Th e m ixture was com bin ed with th e reaction m ixture obtain ed from th e startin g
com poun d 1 (0.26 g, 1 m m ol). After th e eth er was distilled off, silica gel colum n ch rom atog-
raph y (CCl4 as eluen t) of th e residue gave im idoyl ch lorides 2 (0.75 g), wh ich were purified
by dissolvin g in h eptan e (5 m l) an d passin g th rough a silica gel layer. Th e solven t was dis-
tilled off an d im idoyl ch lorides 2 were isolated as yellow oil (0.66 g, 69%), wh ich solidified.
M.p. 40–43 °C. Accordin g to GC/MS data, th e m ixture con tain ed about 97% of 2a an d about
3% of 2b. For C13H4ClF6N calculated: 48.30% C, 1.24% H, 10.00% Cl, 4.33% N, 322.9936
M; foun d: 49.34% C, 1.55% H, 10.02% Cl, 4.00% N, 322.9934 M. Th e secon d fraction (0.18 g)
was a m ixture of isom eric azom eth in es 3, wh ich was purified by sublim ation at 100 °C/1330 Pa
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

1460
Petrova et al.:
TABLE I
MS an d IR data for im idoyl ch lorides 2a, 4, 7, azom eth in es 3a, 3b, 5, am ide 8 an d 1,2,3,4-
tetrah ydroquin azolin e-2,4-dion es 9a–9d
Com p.
MS, m /z, %
IR, ν, cm –1
2a
[M]+ 323 (22.96), [M – Cl]+ 288 (100), [M – Cl – F]+ 269 (1.35),
[C6F5]+ 167 (3.88), [C6H4F]+ 95 (55.12)
977–994 s, 1159 m , 1240 s,
1510–1514 vs (C6F5), 1598 m ,
1643–1659 s (C=N), 2858 w,
2931 w, 2963 w (C–H)
3a
[M]+ 383 (80.15), [M – F]+ 364 (10.77), [M – C6H4F]+ 288 (77.68), 986–998 vs, 1155 m , 1240 s,
[M – C6F5N – H]+ 201 (100), [C6F5]+ 167 (3.37), [C5F3]+ 117
(6.82), [C6H4F]+ 95 (72.28)
1308 m , 1504–1514 vs (C6F5),
1602 s, 1627 m (C=N),
3083 w (C–H)
3b
4
[M]+ 383 (57.41), [M – F]+ 364 (7.33), [M – C6H4F]+ 288 (100),
[M – C6F5N – H]+ 201 (77.87), [C6F5]+ 167 (7.13), [C6H4F]+ 95
(80.35)
[M]+ 359 (15.55), [M – Cl]+ 324 (100), [M – Cl – C6H2F3]+ 193
939 s, 1002 s, 1126 s (C–F),
1446 s, 1508–1515 vs (C6F5),
1597 s, 1639 vs (C=N),
3107 w (C–H)
(1.93), [C6F5]+ 167 (21.39), [C5F3]+ 117 (24.91)
5
7
[M]+ 455 (50.62), [M – F]+ 436 (11.02), [M – C6H2F3]+ 324 (100), 979 s, 1001 s, 1051 s, 1129 s,
[M – NCC6H2F3]+ 298 (8.04), [C6F5]+ 167 (14.65), [C5F3]+ 117
(14.69)
1447 m , 1510–1517 vs
(C6F5), 1600 m , 1678 s (C=N),
3108 w (C–H)
[M]+ 377 (20.12), [M – Cl]+ 342 (100), [M – Cl – F]+ 323 (2.11),
[M – Cl – C6F4H]+ 193 (1.39), [C6F5]+ 167 (25.63), [C5F3]+ 117
(33.57)
1001 s (C–F), 1514 vs (C6F5),
1681 m (C=N)
8
[M]+ 359 (11.13), [M – C6F5NH]+ 177 (100), [M – C6F5NHCO]+
149 (35.32), [C5F3]+ 117 (2.63)
9a
[M]+ 564 (12.60), [M – F]+ 545 (0.52), [M – C6F5NCO]+ 355
(100), [M – C6F5NCO – CO]+ 327 (11.59),
[M – C6F5NCO – CO – F]+ 308 (35.90), [M – C6F5NCO – CO – Cl]+
292 (26.89), [M – C6F5NCO – CO – CF2]+ 277 (17.08),
[C6F5NCO]+ 209 (6.69), [C6F5N]+ 181 (4.93)
9b
[M]+ 564 (48.62), [M – F]+ 545 (1.57), [M – C6F5NCO]+ 355
(100), [M – C6F5NCO – CO]+ 327 (12.60),
[M – C6F5NCO – CO – F]+ 308 (17.18), [M – C6F5NCO – CO – Cl]+
292 (18.35), [M – C6F5NCO – CO – CF2]+ 277 (7.48), [C6F5NCO]+
209 (0.74), [C6F5N]+ 181 (1.02)
9c
9d
[M]+ 596 (41.85), [M – C6F5NCO]+ 387 (100),
[M – C6F5NCO – Cl]+ 352 (22.97), [M – C6F5NCO – Cl – CO]+ 324
(27.01), [M – C6F5NCO – CO – 3Cl]+ 254 (10.84), [C6F5NCO]+
209 (4.13)
[M]+ 598 (8.63), [M – C6F5NCO]+ 389 (100),
999 s (C–F), 1200 vs, 1523 vs
[M – C6F5NCO – CO – F]+ 342 (17.16), [M – C6F5NCO – CO – Cl]+ (C6F5), 1711 vs (C=O), 1748 s
326 (18.52), [M – C6F5NCO – CO – 2Cl – F]+ 272 (6.16),
[C6F5NCO]+ 209 (5.70)
(C=O) (CHCl3)
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

N-(Pentafluorophenyl)carbonimidoyl Dichloride
1461
an d recrystallization from petroleum eth er. M.p. 74–76 °C; com position (GC/MS data): 52%
of 3a, 42% of 3b, an d 6% of 3c. Accordin g to 19F NMR data, th e ratio of 3a : 3b was 1.1 : 1.
For C19H8F7N calculated: 59.50% C, 2.09% H, 34.73% F, 3.66% N, 383.0545 M; foun d:
59.11% C, 2.11% H, 34.59% F, 3.57% N, 383.0535 M. The third fraction (0.13 g) was also a mix-
ture of azomethines 3, in which 3a prevailed. It was purified by sublimation at 100 °C/1 330 Pa
an d recrystallization from petroleum eth er. M.p. 104–112 °C; com position (GC/MS data):
95% of 3a, 3% of 3b, an d 2% of 3c. For C19H8F7N calculated: 59.50% C, 2.09% H, 34.73% F,
3.66% N, 383.0545 M; foun d: 59.86% C, 2.24% H, 34.62% F, 3.63% N, 383.0535 M. Th e total
yield of azom eth in es 3 was 27%.
TABLE II
NMR data for im idoyl ch lorides 2a, 4, 7, azom eth in es 3a, 3b, 5 an d am ide 8
p
3' 4'
p
F,H
5'
m
2'
F
m
F
3
2
o
6'
Cl
C
cis
o
4
N
C
p
2
NHCO
X
F
F
N
2
trans
6
5
m
o
6
3
6
3
F,H
5
4
F,H
trans
8
3a, 3b, 5
2a, 4, 7
5
4
19
F NMR, δ, ppm (in tegral in ten sity); J, Hz (solven t)
1
H NMR
Com p.
δ, ppm (solven t)
F
F
F
F
(F
)
F
F (F )
4 4′
o
p
m
2,6
2′,6′
3,5
2a
3a
8.20 m (H-2, H-6), 11.70 m (2)
7.15 m (H-3, H-5)
1.60 tt (1)
–0.78 m (2)
–1.38 m (2)
57.75 tt
J(4,2)=J(4,6)=5
J(4,3)=J(4,5)=8.5
7.75 m (H-2, H-6) 10.07 m (2)
7.18–6.99 m , 6 H
–0.81 tt (1)
55.70 tt (1)
J(4,2)=J(4,6)=5.5
J(4,3)=J(4,5)=8.3
(53.11 tt (1))
J(4′,2′)=J(4′,6′)=5.5
J(4′,3′)=J(4′,5′)=8.3
3b
4
7.77 m (H-2, H-6) 10.67 m (2)
7.08 m , 5 H
7.36 m , 1 H
–0.68 m (1) –1.66 m (2) 50.36 m (1)
(F
55.70 m (1)
)
2′
6.79 m (H-3, H-5) 12.46 m (2)
2.82 t (1)
1.69 t (1)
–0.32 m (2) 54.97 m (2)
60.80 tt (1)
J(4,3)=J(4,5)=8
J(4,2)=J(4,6)=8
60.01 tt (1) tran s
J(4,3)=J(4,5)=8
J(4,2)=J(4,6)=8
(59.44 tt (1) cis)
J(4′,3′)=J(4′,5′)=8
J(4′,2′)=J(4′,6′)=8
5
6.74 m (H-3, H-5) 11.02 m (2)
tran s
6.62 m (H-3′, H-5′)
cis
–0.72 m (2) 54.20 bs (2)
tran s
(52.90 m (2)
cis)
7
8
7.05 m (H-4)
(h exan e)
13.11 m (2)
(h exan e)
3.48 t (1)
5.77 t (1)
0.01 m (2)
22.74 m (2)
25.57 m (2)
24.86 m (2)
9.84 c (NH)
7.55 m (H-4)
(eth er)
18.40 m (2)
(eth er)
–0.55 m (2) 21.57 m (2)
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

1462
Petrova et al.:
Th e experim en t of com poun d 1 (0.26 g, 1 m m ol) at 120 °C (17 h ) was perform ed in a
sealed glass am poule. Th e reaction m ixture was treated as described above, eth er was dis-
tilled off an d th e solid residue was wash ed with a sm all am oun t of petroleum eth er (0.5 m l).
Th is gave 0.15 g (40%) of a m ixture of azom eth in es 3, wh ich was purified by sublim ation at
105 °C/1 330 Pa givin g 0.12 g of a m ixture con tain in g 88% of 3a, 9% of 3b, an d 3% of 3c;
m .p. 89–107 °C. Accordin g to 19F NMR data, th e m ixture con tain ed isom ers 3a an d 3b in
th e ratio 10 : 1.
Reactions with 1,3,5-Trifluorobenzene
Carbon im idoyl dich loride 1 (0.26 g, 1 m m ol), fresh ly sublim ated AlCl3 (0.34 g, 2.5 m m ol),
an d 1,3,5-trifluoroben zen e (0.52 g, 4 m m ol) were m ixed in a flask with a reflux con den ser
an d a calcium ch loride tube at a bath tem perature of 50–60 °C (17 h ). Th e reaction m ixture
was treated as described above an d an alyzed by 19F NMR an d GC/MS.
Th e reaction at 85 °C (17 h ) an d with an alogous batch of reagen ts was accom plish ed in a
sealed glass am poule. Th e residues of two run s after evaporation were com bin ed an d frac-
tion ated on a silica gel colum n (h exan e). Th is gave 0.16 g of 2,4,6-trifluoro-N-(pen tafluoro-
ph en yl)ben zim idoyl ch loride (4), solidifyin g on storage (98% purity). M.p. 30–33.5 °C. For
C
13H2ClF8N calculated: 358.9748 M; foun d: 358.9742 M. Usin g CCl4 as eluen t, 0.45 g (50%)
of bis(2,4,6-trifluoroph en yl) keton e N-(pen tafluoroph en yl)im in e (5) with m .p. 91–94 °C was
obtain ed. For C19H4F11N calculated: 50.11% C, 0.88% H, 45.93% F, 3.08% N, 455.0158 M;
foun d: 50.65% C, 0.60% H, 46.29% F, 3.18% N, 455.0157 M.
Th e reaction s at 120 °C (22 h ) an d 170 °C (20 h ) with th e above batch es were also carried
out in sealed am poules. Th e reaction m ixtures from 3 run s at 170 °C were com bin ed, th e
solven t was distilled off an d th e residue was separated on a silica gel colum n (CCl4) yieldin g
0.6 g (44%) of azom eth in e 5, purified by recrystallization from petroleum eth er. M.p. 94–95 °C.
TABLE III
NMR data for 1,2,3,4-tetrah ydroquin azolin e-2,4-dion es 9
19
F NMR, δ, ppm (in tegral in ten sity); J, Hz
1
H NMR
δ, ppm ; J, Hz
Com p.
F
F
F
F
F
8
o
p
m
6
9a
9b
7.30 dd (H-7) 17.66 m (2)
12.02 t (1)
11.61 t (1)
1.08 m (4)
51.35 dd (1)
J(6,7)=7.63
J(6,8)=5.22
39.52 dd (1)
J(8,7)=12.20
J(8,6)=5.22
J(7,6)=7.63
16.07 m (2)
J(7,8)=12.20
7.96 dd (H-5) 17.71 m (2)
12.60 t (1)
11.77 t (1)
1.51 m (2)
1.09 m (2)
48.36 dd (1)
J(6,5)=7.32
J(6,8)=1.60
39.20 bs (1)
J(5,6)=7.32
J(5,8)=1.83
16.36 m (2)
9c
9d
8.36 s (H-7)
17.84 m (4)
12.30 m (1)
11.82 m (1)
1.05 (4)
18.49 m (2)
17.26 m (2)
12.65 t (1)
11.75 t (1)
1.39 m (2)
0.97 m (2)
51.15 d (1)
J(6,8)=2.03
39.80 bs (1)
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

N-(Pentafluorophenyl)carbonimidoyl Dichloride
1463
Reactions with 1,2,4,5-Tetrafluorobenzene
Com poun d 1 (0.26 g, 1 m m ol), AlCl3 (0.34 g, 2.5 m m ol), an d 1,2,4,5-tetrafluoroben zen e (1 g,
6.7 m m ol) were h eated in an am poule (170 °C, 31 h ). Th e residue after evaporation (0.45 g)
was treated with a sm all am oun t of petroleum eth er (1 m l), an d th e un dissolved residue
(0.12 g) con tain in g am ide 8, com poun d 9a, an d urea 10 in th e ratio 1 : 1 : 1 (19F NMR) was
filtered off. Th is residue was dissolved in CCl4 (1.5 m l), an d th e un dissolved part (0.05 g)
con tain in g am ide 8, com poun d 9a, an d urea 10 in th e ratio 10 : 1 : 10 was filtered off. For
am ide 8, C13H2F9NO calculated: 358.9993 M; foun d: 358.9990 M. Th e CCl4 solution was
evaporated to dryn ess an d th e solid residue (0.07 g) was sublim ed at 160 °C/933 Pa an d
recrystallized from petroleum eth er to give 5-ch loro-6,8-difluoro-1,3-bis(pen tafluoroph en yl)-
1,2,3,4-tetrah ydroquin azolin e-2,4-dion e (9a), wh ere th e con ten t of th e m ajor substan ce was
about 91% (3% 9b an d oth er m in or com pon en ts, GC/MS). M.p. 185–190 °C, yield 12.5%.
For C20H1Cl1F12N2O2 calculated: 563.9535 M; foun d: 563.9549 M. Th e petroleum eth er fil-
trates obtain ed from two run s were com bin ed, th e solven t was distilled off, an d th e residue
was fraction ated on a silica gel colum n (CCl4). Fraction 1 (0.25 g) con tain ed th e startin g
com poun ds, th e products of ch lorin e exch an ge for fluorin e in tetrafluoroben zen e, im idoyl
ch loride 7, an d oth er m in or com pon en ts (GC/MS). Repeated silica gel ch rom atograph y of
th is fraction (h exan e) gave im idoyl ch loride 7 (0.03 g, 4%). For C13H1Cl1F9N calculated:
376.9654 M; foun d: 376.9670 M. Fraction 2 (0.02 g) con tain ed 80% of 9c, 1% of 9a an d 9b,
alon g with a large am oun t of m in or im purities (GC/MS). Th e yield of 9c was 3%. For
C
20H1Cl3F10N2O2 calculated: 595.8944 M; foun d: 595.8937 M. Fraction 3 (0.04 g) was puri-
fied by sublim ation at 160 °C/933 Pa an d recrystallization from petroleum eth er. It con -
tain ed com poun d 9b (about 86% purity, GC/MS) with an adm ixture of h eterocyclic
com poun ds 9 with two an d th ree ch lorin e atom s, h avin g close reten tion tim es. M.p.
176–181 °C. For 9b, C20H1Cl1F12N2O2 calculated: 563.9535 M; foun d: 563.9549 M.
Reactions with Pentafluorobenzene
A m ixture of com poun d
1 (0.26 g, 1 m m ol), AlCl3 (0.34 g, 2.5 m m ol), an d pen ta-
fluoroben zen e (1 g, 5.9 m m ol) was h eated in an am poule at 170 °C (31.5 h ) gave, after evap-
oration , 0.29 g of a viscous solid residue. Th e residues from th ree experim en ts were
com bin ed (0.88 g), treated with CCl4 (3 m l), an d th e un dissolved solid (0.11 g) was filtered
off to give a m ixture of urea 10 an d am ide 12 in th e ratio 1.5 : 1 (19F NMR). Th e filtrate was
ch rom atograph ed on a silica gel colum n (CCl4). Fraction 1 (0.18 g) con tain ed startin g com -
poun d 1 (30%), im idoyl ch loride 11 (17%), an d th e products of ch lorin e exch an ge for fluo-
rin e in pen tafluoroben zen e, in cludin g h exach loroben zen e (11%, GC/MS). Th e ratio of th e
startin g com poun d 1 an d im idoyl ch loride 11 was 2 : 1 (19F NMR). Fraction 2 (0.22 g) con -
tain ed com poun d 9d , wh ich was purified by sublim ation at 140 °C/1 330 Pa an d
recrystallization from petroleum eth er. M.p. 145–147.5 °C, yield of 9d 24%. For
C
20Cl2F12N2O2 calculated: 40.07% C, 11.85% Cl, 38.06% F, 4.67% N, 597.9145 M; foun d:
39.71% C, 11.66% Cl, 38.11% F, 4.24% N, 597.9151 M.
Reaction of 1 with Im idoyl Ch loride 11 in th e Presen ce of AlCl3
A m ixture of com poun d 1 (0.26 g, 1 m m ol), im idoyl ch loride 11 (0.4 g, 1 m m ol), an d
fresh ly sublim ated AlCl3 (0.34 g, 2.5 m m ol) was h eated in a sealed glass am poule at 170 °C
(31 h ). Th e reaction m ixture was cooled an d decom posed with cold water (100 m l). Th e
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

1464
Petrova et al.:
ligh t-colored residue was filtered off, wash ed with water to n eutral pH an d dried on air. Th is
residue was dissolved in eth er (100 m l), th e un dissolved in organ ic residue (0.05 g) was fil-
tered off an d th e solution was an alyzed by GC/MS an d 19F NMR. Accordin g to GC/MS data,
th e solution con tain ed 80% of 9d with an adm ixture of trace am oun ts of h eterocyclic deriv-
atives of type 9 con tain in g differen t n um bers of fluorin e an d ch lorin e atom s in th e
carbocyclic rin g, products of ch lorin e exch an ge for fluorin e in th e startin g im idoyl ch loride
11, an d un iden tified com poun ds (m axim um 5%). Th e solven t was distilled off to give 0.45 g
of th e solid residue, from wh ich com poun d 9d was separated by recrystallization from petro-
leum eth er. Yield 55%.
X-Ray Structure An alysis of Com poun ds 9d , 3a an d 3b
A Bruker P4 diffractom eter (m on och rom atic MoKα radiation , θ/2θ scan s, 2θ < 50°) was used
to m easure th e un it cell dim en sion s an d to collect data for com poun d 9d . Crystallograph ic
data for com poun d 9d : C20Cl2F12N2O2, Mw = 599.12, crystal class m on oclin ic, space group
P21/n, a = 22.034(3) Å, b = 8.7048(8) Å, c = 22.655(3) Å, β = 107.672(9)°, V = 4 140.2(8) Å3,
Z = 8, dcalc = 1.922 g/cm 3, µ = 0.446 m m –1, crystal size 0.30 m m × 0.42 m m × 0.46 m m . Ab-
sorption correction s by em pirical m eth od based on ψ-scan s were applied (tran sm ission
0.43–0.63). Th e structure was solved by direct m eth ods (SHELXS97) an d refin ed by a full
m atrix least-squares procedure (SHELXL97) usin g an isotropic th erm al param eters. Th e fin al
in dexes are wR2 = 0.1801, S = 1.015 for all 7 238 F2 an d R1 = 0.0597 for 4 629 Fo > 4σ.
Crystal structure of th e first m olecule from two crystallograph ically in depen den t on es is
sh own in Fig. 1. Th e quin azolin e fragm en t is plan ar with root m ean square (Rm s) deviation
0.019 an d 0.010 Å accordin gly for two m olecules. Th e an gles between th e quin azolin e an d
Cl5
C5
F19
C18
F15
C19
C20
O2
F18
C4A
C4
F6
C17
C6
C7
C15
C16
F16
N3
C2
F17
C8A
C8
Cl7
F10
N1
C9
O1
C10
F8
C14
F11
C11
C12
F14
C13
F12
F13
FIG. 1
ORTEP diagram of 5,7-dich loro-6,8-difluoro-1,3-bis(pen tafluoroph en yl)-1,2,3,4-tetrah ydro-
quin azolin e-2,4-dion e (9d )
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

N-(Pentafluorophenyl)carbonimidoyl Dichloride
1465
ben zen e plan es are equal to 76.3(1) (69.4(1)°) for C15–C20 an d 78.6(1) (88.2(1)°) for
C9–C14. Bon d len gth s in th e quin azolin e m oiety are alm ost th e sam e as in 3-am in o-
6-brom o-1-m eth yl-1,2,3,4-tetrah ydroquin azolin -2,4-dion e11. It is n ecessary to n ote a stron g
in term olecular con tacts (Cl5···Cl5′ 3.328(2) Å) an d ligh t sh orted in term olecular con tacts12
(Cl5···F17 3.058(3), Cl7′···F10 3.163(3), Cl7′···F16 3.142(3), Cl7···O1′ 2.952(3), F12···F12′
2.717(6) Å).
X-Ray structure an alysis of th e sin gle crystal grown from a m ixture of com poun ds 3a an d
3b in petroleum eth er was carried out on a Syn tex P21 difractom eter (CuKα radiation with
graph ite m on och rom ator, θ/2θ scan s, 2θ < 140°). Crystallograph ic data: C19H8F7N, Mw
383.26, crystal class m on oclin ic, space group P21/c, a = 9.326(1) Å, b = 17.703(2) Å, c =
10.539(1) Å, β = 110.888(10)°, V = 1 625.7(4) Å3, Z = 4, dcalc = 1.566 g/cm 3, µ = 1.322 m m –1
=
,
crystal size 0.10 m m × 0.20 m m × 0.50 m m . Absorption correction s by th e in tegration
m eth od were applied (tran sm ission 0.64–0.88). Th e structure was solved by direct m eth ods
(SHELXS97) an d refin ed by
a full-m atrix least-squares procedure (SHELXL97) usin g
an isotropic th erm al param eters. Th e fin al in dexes are wR2 = 0.2290, S = 1.042 for all 3 076 F2
an d R1 = 0.0685 for 1 712 Fo > 4σ.
Molecular structure of com poun ds 3a an d 3b is sh own in Fig. 2. In crystallin e ph ase com -
poun ds 3a an d 3b are m ixed in th e 3 : 2 ratio sin ce th e localization probabilities of fluorin e
atom in th e ben zen e rin g of C9–C14 are equal to 61.6(7) an d 38.4(7)% for para (F12 atom )
F6
C6
F12
F5
C12
C11
C13
C14
F7
C5
C4
F4
C7
C8
F8
C10
F10
C9
C3
C2
N1
C15
C16
C17
C18
C20
C19
F18
FIG. 2
ORTEP diagram of bis(4-fluoroph en yl) keton e N-(pen tafluoroph en yl)im in e (3a) an d
(2-fluoroph en yl) (4-fluoroph en yl) keton e N-(pen tafluoroph en yl)im in e (3b) m ixture (3 : 2)
Collect. Czech. Chem. Commun. (Vol. 67) (2002)

1466
Petrova et al.:
an d ortho (F10 atom ) position s, respectively. Th e C3–N1=C2(C9)–C15 fragm en t is plan ar
with Rm s deviation 0.015 Å an d its an gles with ben zen e rin gs C15–C20, C9–C14 an d C3–C8
plan es are 15.9(2), 66.1(2) an d 70.7(1)°, respectively. Th e con form ation an d geom etry
of com poun ds un der in vestigation are alm ost th e sam e as, for exam ple, in 2-[an ilin o-
(ph en yl)m eth yl] ph en ol13. CCDC 179891 (for 9d ) an d CCDC 179892 (for 3a + 3b) con tain
th e supplem en tary crystallograph ic data for th is paper. Th ese data can be obtain ed free of
ch arge via www.ccdc.cam .ac.uk/con ts/retrievin g.h tm l (or from th e Cam bridge Crystallo-
graph ic Data Cen tre, 12, Un ion Road, Cam bridge, CB2 1EZ, UK; fax: +44 1223 336033; or
deposit@ccdc.cam .ac.uk).
The authors are grateful to the Russian Foundation for Fundamental Research for financial support
in obtaining the Cambridge Structural Database licence (project 99-07-90133).
REFERENCES
1. Petrova T. D., Platonov V. E.: Zh. Org. Khim. 1997, 33, 745; Russ. J. Org. Chem. (Engl.
Transl.) 1997, 33, 684.
2. Petrova T. D., Platonov V. E., Kolesnikova I. V., Ribalova T. V., Bagryanskaya I. Yu.,
Gatilov Yu. V.: J. Fluorine Chem. 2000, 103, 63.
3. Petrova T. D., Kolesnikova I. V., Mamatyuk V. I., Vetchinov V. P., Platonov V. E.,
Bagryanskaya I. Yu., Gatilov Yu. V.: Russ. Chem. Bull. (Engl. Transl.) 1993, 42, 1540.
4. Dondoni A., Exner O.: J. Chem. Soc., Perkin Trans. 2 1972, 1908.
5. Sheppard W. A., Sharts C. M.: Organic Fluorine Chemistry (Russ. Transl.), p. 14. Mir,
Moscow 1972.
6. Patinkin S. H., Friedman B. S. in: Friedel–Crafts and Related Reactions (G. A. Olah, Ed.),
Part I, Vol. 2, p. 66. Wiley, New York–London–Sydney 1964.
7. Emsley J. W., Feeney J., Sutcliffe L. H.: High Resolution Nuclear Magnetic Resonance
Spectroscopy (Russ. Transl.), Vol. 2, p. 224. Mir, Moscow 1969.
8. Vlasov V. M. in: Reactivity of Polyfluoroaromatic Compounds (Russ. Transl.) (G. G.
Yakobson, Ed.), p. 193. Nauka, Novosibirsk 1983.
9. Dvornikova K. V., Platonov V. E., Yakobson G. G.: Zh. Org. Khim. 1991, 27, 609; Russ. J.
Org. Chem. (Engl. Transl.) 1991, 27, 525.
10. Savchenko T. I., Kolesnikova I. V., Petrova T. D., Platonov V. E.: J. Fluorine Chem. 1983,
22, 439.
11. Ardebili M. H. P., White J. G.: Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem.
1978, 34, 2890.
12. Zefirov Yu. V., Porai-Koshits M. A.: Zh. Strukt. Khim. 1980, 21, 150; J. Struct. Chem. (Engl.
Transl.) 1980, 21, 526.
13. Leardini R., McDougald G., McDougald H., McNab H., Nanni D., Parsons S.: Acta
Crystallogr., Sect. C: Cryst. Struct. Commun. 1998, 54, 1360.
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