Hydrohalogenation reactions of 1,2-allenic sulfones. A novel synthesis of 2-haloallylic sulfones

Full text of DOI:10.1021/jo981592v

1
026
J . Org. Chem. 1999, 64, 1026-1028
Hyd r oh a logen a tion Rea ction s of 1,2-Allen ic
Su lfon es. A Novel Syn th esis of 2-Ha loa llylic
Su lfon es
Sch em e 1
Shengming Ma* and Qi Wei
Laboratory of Organometallic Chemistry, Shanghai Institute
of Organic Chemistry, Chinese Academy of Sciences, 354
Fenglin Lu, Shanghai 200032, People’s Republic of China
Received August 5, 1998
In tr od u ction
Hydrohalogenation reactions of electron-deficient C-C
1
1
triple bonds, i.e., 2-alkynoic acids, 2-alkynonates,
Sch em e 2a
1
1
1
2
-alkynamides, 2-propyne nitriles, 2-alkynones, 1-alkyn-
yl phosphonates, 1-alkynyl sulfoxides, 1-alkynyl tri-
flone, 1-alkynyl iodinium salts, etc., have become a very
powerful tool for the highly stereoselective synthesis of
2
3
4
5
3
-halo-(2Z)-alkenoic acids and the corresponding equiva-
lents. Another class of compounds attracting our interest
is electron-deficient 1,2-dienes. Due to the unique ar-
rangement of the two sets of π-orbitals, the reactivity of
electron-deficient 1,2-dienes should be higher than that
a
Conditions A: MX (M ) Na or Li), HOAc (solvent). Conditions
6
of the corresponding alkynes. Recently, we developed a
B: MX (M ) Na or Li), HOAc (1 equiv), CH3CN (solvent).
Conditions C: HX (as the solvent and the reagent).
methodology for the efficient syntheses of 3-halo-3-
butenoic acids/methyl esters and 4-halo-4-penten-2-ones
via the hydrohalogenation reactions of 2,3-butadienoic
acid/methyl ester and 3,4-pentadien-2-one, respectively.7
In this paper, we wish to disclose our recent results on
the corresponding hydrohalogenation reactions of 1,2-
allenic sulfones.
a general, clean, and high-yielding method for the ef-
ficient synthesis of the title compounds is highly desir-
able.
Resu lts a n d Discu ssion
The known methods for the synthesis of these com-
pounds are (1) the oxidation of 2-chloroallyl sulfide,
which could be prepared via the reaction of thiophenols
1,2-Allenic sulfones are readily available from the
oxidation of their corresponding sulfoxides, which can be
easily prepared from the reaction of propargylic alcohols
with RSCl (Scheme 1).12 Four such compounds were
synthesized via the chemistry shown in Scheme 1.
Three sets of reaction conditions were established to
carry out the hydrohalogenation reactions of 1,2-allenic
sulfones with metallic halides (Scheme 2). Some typical
results are summarized in Table 1 and Table 2.
8
with the corresponding 2,3-dihalopropenes; (2) the reac-
tion of 1-(phenylsulfonyl)propyne with hydrazonyl chlo-
rides to afford a mixture of the allylic sulfone, the vinylic
9
sulfone, and many other products; (3) the radical addi-
tion of alkylsulfonyl iodide with allenes to produce a
1
0
mixture of several adducts; (4) the reaction of 2-haloallyl
iodides with PhSO
2
Na.11 It should be noted that 2-ha-
loallyl iodides, especially the bromo and iodo analogues,
are not stable and usually are not readily available. Thus,
From the results of the hydrohalogenation reactions
shown in Tables 1 and 2, as well as the results with
allenic ketones, carboxylic acids, and esters, the following
conclusions are obvious. (1) The electron-withdrawing
(1) Ma, S.; Lu, X. J . Chem. Soc., Chem. Commun. 1990, 1643. Ma,
S.; Lu, X. Tetrahedron Lett. 1990, 31, 7653. Ma, S.; Lu, X.; Li, Z. J .
Org. Chem. 1992, 57, 709. Lu, X.; Zhu, G.; Ma, S. Chin. J . Chem. 1993,
ability of SO
2
R is somewhat similar to that of the
carbonyl group in esters and is much weaker than that
1
1, 267. Ma, S.; Lu, X. Org. Synth. 1995, 72, 112.
1
3
(2) Huang, X.; Zhang, C.; Lu, X. Synthesis 1995, 769.
of keto groups (compare the results with that in ref 7).
(
3) de la Pradilla, R. F.; Morente, M.; Paley, R. S. Tetrahedron Lett.
A very slow reaction of 3a with LiI in HOAc at room
temperature was observed. (2) The migration of the
1
992, 33, 6101.
4) Xiang, J .; J iang, W.; Gong, J .; Fuchs, P. L. J . Am. Chem. Soc.
997, 119, 4123.
5) Ochiai, M.; Uemura, K.; Oshima, K.; Masaki, Y.; Kunishima, M.;
Tani, S. Tetrahedron Lett. 1991, 32, 4753.
6) (a) Schuster, H. F.; Coppola, G. M. Allenes in Organic Synthesis;
(
1
CdC bond in product 4a c was not observed even when
(
7,9
4
a c was heated in HOAc at 118 °C for 11 h. (3) For
(
the synthesis of the iodides, both NaI and LiI worked
well, although the yield with LiI was higher under the
same reaction conditions (compare entries 1 with 2 in
Table 1), while for bromides and chlorides, lithium salts
afforded the products in much higher yields than those
J ohn Wiley & Sons: New York, 1988. (b) The Chemistry of Ketenes,
Allenes, and Related Compounds; Patai, S., Ed.; J ohn Wiley & Sons:
New York, 1980; Part 1.
(
7) Ma, S.; Shi, Z.; Li, L. J . Org. Chem. 1998, 63, 4522.
(8) Takeshita, H.; Motomura, H.; Mametsuka, H. Bull. Chem. Soc.
J pn. 1984, 57, 3156. Stirling, C. J . M. J . Chem. Soc. Suppl. 1964, 5875.
(
(
9) Bruch e´ , L.; Zecchi, G. J . Heterocycl. Chem. 1983, 20, 1705.
10) Truce, W. E.; Heuring, D. L.; Wolf, G. C. J . Org. Chem. 1974,
(12) Brandsma, L.; Verkruijsse, H. D. Synthesis of Acetylenes, Allenes
and Cumulenes; Elsevier Scientific Publishing Company: New York,
1981; pp 197, 198, and 215.
(13) House, H. O. Modern Synthetic Reaction, 2nd ed.; The Benjamin/
Cummings Publishing Company: Menlo Park, CA, 1972; p 494.
3
9, 238.
11) Baldwin, J . E.; Adlington, R. M.; Lowe, C.; O’Neil, I. A.; Sanders,
G. L.; Schofield, C. J .; Sweeney, J . B. J . Chem. Soc., Chem. Commun.
988, 1030.
(
1
1
0.1021/jo981592v CCC: $18.00 © 1999 American Chemical Society
Published on Web 01/20/1999

Notes
J . Org. Chem., Vol. 64, No. 3, 1999 1027
Ta ble 1. Hyd r oh a logen a tion Rea ction s of 1,2-Allen ic
Su lfon e (3a )
Sch em e 3
temp time
yield
entry
MX (equiv)
condns
(°C)
(h)
product (%)a
1
2
3
4
5
6
7
8
9
NaI (1.1-2)
LiI (1.7)
A
A
A
A
A
A
B
B
B
C
C
80
0.5
0.5
4
4a a
4a a
4a b
4a b
4a c
4a c
4a a
4a b
4a c
4a a
4a c
80
87
61
79
28
83
76
76
85
65
83
reflux
reflux
reflux
reflux 11
reflux 11
80
80
80
80
80
b
c
NaBr (2)
.
LiBr H2O (2)
1.5
NaCl (4.4)
LiCl‚H2O (5)
LiI (2)
12
12
12
8
LiBr‚H2O (2)
LiCl‚H2O (2)
d
1
1
0
1
HI
e
HCl
8
a
b
Isolated yield, unless otherwise stated. 30% of 3a was
c
d
recovered. 70% of 3a was recovered. Aqueous acid (45%) was
used. Aqueous acid (37%) was used.
e
Ta ble 2. Hyd r oh a logen a tion Rea ction s of 3b-d
(0.1 mmol), and 3d (0.1 mmol) with NaI (0.1 mmol) in
temp time
condns (°C)
yield
HOAc at 85 °C for 4 h afforded the hydroiodination
product 4ba in 69% NMR yield, while the formations of
4ca and 4d a were not observed during the specified
reaction time (Scheme 3).
entry
3
MX (equiv)
(h) product (%)a
1
2
3
4
5
6
7
8
9
3b NaI (2)
3b LiBr H2O (2)
3b NaBr (5)
3b LiCl‚H2O (2)
3b NaCl (5)
3b LiI (2.5)
A
A
A
A
A
B
B
B
C
C
C
A
A
A
A
A
A
A
80
90
90
0.5
0.5
8
4ba
4bb
4bb
4bc
4bc
4ba
4bb
4bc
4ba
4bb
4bc
4ca
4ca
4cb
4cb
4cb
4d a
4d a
82
78
67
69
14
76
67
76
44
53
81
88
83
77
74
.
In summary, the hydrohalogenation reaction of 1,2-
allenic sulfones afforded 2-haloallyl sulfones in high
yields using conditions A, B, and C. Allylic sulfones are
a class of compounds with significant synthetic poten-
tial: (1) the R-positions can be regioselectively alky-
90
2
b
90
13
80
80
80
12
12
12
3b LiBr‚H2O (2.5)
3b LiCl‚H2O (2.5)
c
3b HI
3b HBr
3b HCl
3c NaI (3.5)
3c NaI (1.2)
3c LiBr‚H2O (5)
3c LiBr‚H2O (2)
3c NaBr (5)
3d NaI (3)
80
0.5
14
lated; (2) the sulfone groups can be easily removed by
d
1
1
1
1
1
1
1
1
1
0
1
2
3
4
5
6
7
8
80
80
80
22
22
4
15
N H
reduction; (3) the nucleophilic (S 2′) and radical (S 2′)
e
1
6
allylic substitution reactions can take place. Vinyl
halides, especially iodides and bromides, are novel start-
ing materials for radical reactions and transition metal
catalyzed C-C bond formation reactions. All these make
reflux
110
4
20
reflux 10
110
reflux
20
2
41f
74
69
2
-haloallylic sulfones prepared by the method described
in this paper valuable synthetic intermediates. The
investigation regarding the synthetic utility of these
compounds is currently being carried out in our labora-
tory.
3d NaI (1.2)
reflux 2.5
a
b
Isolated yield, unless otherwise stated. 36% of 3b was
c
d
recovered. Aqueous acid (45%) was used. Aqueous acid (40%)
was used. e Aqueous acid (37%) was used. f NMR yield.
of the sodium salts (compare entries 3 with 4 and 5 with
Exp er im en ta l Section
6
in Table 1, compare entries 2 with 3, 4 with 5, and 14
Gen er a l. NaI, LiI, NaBr, LiBr‚H
2
2
O, NaCl, LiCl‚H O, hydro-
with 16 in Table 2). (4) The reaction can proceed in CH
3
-
chloric acid, hydrobromic acid, hydriodic acid, and acetic acid
CN using only 1 equiv of HOAc (conditions B). (5) The
reaction of HX with 1,2-allenic sulfones also afforded the
hydrohalogenation products in reasonable yields (entries
1
are commercially available and used as is. H NMR spectra were
measured using CDCl
3 4
as the solvent and Me Si as the internal
standard. The NMR yields were measured using CH Br as the
2
2
1
0 and 11 in Table 1, entries 9-11 in Table 2).
internal standard. 1-(Methylsulfonyl)-1,2-propadiene (3a ), (1,2-
propadienylsulfonyl)benzene (3b), (1-methyl-1,2-propadienyl-
sulfonyl)benzene (3c), and (3-methyl-1,2-butadienylsulfonyl)-
benzene (3d ) were prepared according to the published
This reaction proceeded via a nucleophilic addition of
X- to the R,â CdC bond of the two CdC bonds in 1,2-
allenic sulfones. The proton came from HOAc or HX;
thus, methyl 1-deuterio-2-iodo-2-propenyl sulfone (4a a ′)
could be conveniently prepared via the reaction of 3a with
NaI in DOAc in 77% yield. The extent of D-incorporation
7
12,17
procedure.
Hyd r oh a logen a tion Rea ction s of 1,2-Allen ic Su lfon es.
(a ) Syn th esis of 2-Iod o-3-(m eth ylsu lfon yl)-1-p r op en e (4a a ).
Typ ica l P r oced u r e. Con d ition s A. A solution of 1-(methyl-
sulfonyl)-1,2-propadiene (3a ) (118 mg, 1 mmol) and NaI (165
mg, 1.1 mmol) in HOAc (0.5 mL) was stirred at 80 °C for 1.5 h.
After complete conversion of the starting material as monitored
by TLC (eluent: petroleum ether/ethyl acetate ) 1:1), the
mixture was quenched with water (3 mL), neutralized with
1
is >97% as determined by 300 MHz H NMR and 75.48
MHz 13C NMR spectra (eq 1).
NaHCO
3
, and then extracted with ether (4 × 10 mL). The
combined ether layer was dried over MgSO
4
. Evaporation of the
(
(
14) J o n˜ czyk, A.; Radwan-Pytlewski, T. J . Org. Chem. 1983, 48, 910.
15) Trost, B. M.; Arndt, H. C.; Strege, P. E.; Verhoeven T. R.
The methyl group at the R-position greatly slowed the
hydrohalogenation reaction, probably due to the increase
of steric hindrance at the R-position to pick up a proton
from either HOAc or HX (compare Tables 1 and 2). Even
the two methyl groups in 3d affected the rate of this
reaction. A reaction of a mixture of 3b (0.1 mmol), 3c
Tetrahedron Lett. 1976, 3477. Trost, B. M. Bull. Chem. Soc. J pn. 1988,
6
1, 107.
(16) Chuang, C. Tetrahedron 1991, 47, 5425. Chatgilialoglu, C.;
Ballestri, M.; Vecchi, D. Tetrahedron Lett. 1996, 37, 6383. Chatgilia-
loglu, C.; Alberti, A.; Ballestri, M.; Macciantelli, D. Tetrahedron Lett.
1
996, 37, 6391.
(17) Braverman, S.; Mechoulam, H. Tetrahedron 1974, 30, 3883.

1
028 J . Org. Chem., Vol. 64, No. 3, 1999
Notes
solvent and flash chromatography on silica gel (eluent: petro-
leum ether/ethyl acetate ) 2:1) afforded 197 mg (80%) of 4a a :
solid, mp 56-57 °C (dichloromethane/petroleum ether) (reported:
(f) ((2-Ch lor o-2-p r op en yl)su lfon yl)ben zen e (4bc). Using
2
3b (36 mg, 0.2 mmol) and LiCl‚H O (24 mg, 0.4 mmol) afforded
30 mg (69%) of 4bc: solid, mp 54-55.5 °C (dichloromethane/
1
0
1
8
1
mp 57-58 °C); H NMR 6.57 (d, J ) 1.5 Hz, 1H), 6.25 (d, J )
petroleum ether) (reported: mp 57-58 °C); H NMR δ 7.88 (d,
J ) 7 Hz, 2H), 7.63 (t, J ) 7 Hz, 1H), 7.52 (t, J ) 7 Hz, 2H),
+
1
1
.5 Hz, 1H), 4.12 (s, 2H), 3.00 (s, 3H); MS m/e 247 (M + 1,
+
-1
+
37
2.12), 246 (M , 4.15), 167 (100); IR (KBr) 1600, 1294, 1118 cm
.
5.45 (s, 1H), 5.32 (s, 1H), 4.03 (s, 2H); MS m/e 219 (M + 1 ( -
35
+
Typ ica l P r oced u r e. Con d ition s B. A solution of 1-(meth-
Cl), 1.07), 217 (M + 1 ( Cl), 2.80), 77 (100); IR (KBr) 1628,
1
-
ylsulfonyl)-1,2-propadiene (3a ) (59 mg, 0.5 mmol), HOAc (0.03
mL, 0.52 mmol), and LiI (134 mg, 1 mmol) in acetonitrile (1 mL)
was stirred at 80 °C for 12 h. After complete conversion of the
starting material, the mixture was quenched with water (1 mL),
1320, 1150 cm
.
(
g) ((2-Iod o-1-m eth yl-2-p r op en yl)su lfon yl)ben zen e (4ca ).
Using 3c (29 mg, 0.15 mmol) and NaI (80 mg, 0.53 mmol)
1
afforded 42 mg (88%) of 4ca : liquid; H NMR δ 7.89 (d, J ) 7
neutralized with NaHCO
3
, and then extracted with ether (4 ×
Hz, 2H), 7.67 (t, J ) 7 Hz, 1H), 7.55 (t, J ) 7 Hz, 2H), 6.31 (t,
5
mL). The combined ether layer was dried over MgSO .
4
J ) 2 Hz, 1H), 6.07 (d, J ) 2 Hz, 1H), 3.70(q, J ) 7 Hz, 1H),
Evaporation of the solvent and flash chromatography on silica
+
1
1
.55 (d, J ) 7 Hz, 3H); MS m/e 322 (M , 8.00) 53 (100); IR (neat)
gel (eluent: petroleum ether/ethyl acetate ) 2:1) afforded 93 mg
-1
600, 1300, 1140 cm ; HRMS calcd for C10
11 2
H O IS 321.9523,
(76%) of 4a a .
found 321.9532.
h ) ((2-Br om o-1-m et h yl-2-p r op en yl)su lfon yl)b en zen e
4cb). Using 3c (21 mg, 0.11 mmol) and LiBr‚H O (52 mg, 0.5
mmol) afforded 23 mg (77%) of 4cb: liquid; H NMR δ 7.4-7.9
m, 5H), 5.71 (d, J ) 2 Hz, 1H), 5.63 (d, J ) 2 Hz, 1H), 3.85 (q,
Typ ica l P r oced u r e. Con d ition s C. A solution of 1-(meth-
(
ylsulfonyl)-1,2-propadiene (3a ) (59 mg, 0.5 mmol) and hydriodic
acid (45%, 1 mL) was stirred at 80 °C for 8 h. After complete
conversion of the starting material, the mixture was quenched
(
2
1
(
with water (1 mL), neutralized with NaHCO
tracted with ether (4 × 5 mL). The combined ether layer was
dried over MgSO . Evaporation of the solvent and flash chro-
matography on silica gel (eluent: petroleum ether/ethyl acetate
3
, and then ex-
+
81
J ) 7 Hz, 1H), 1.50 (d, J ) 7 Hz, 3H); MS m/e 276 (M ( Br),
+
79
6
1
2
3.02), 274 (M ( Br), 60.38), 125 (100); IR (neat) 1608, 1300,
4
-1
81
140 cm ; HRMS calcd for C10
11 2
H O BrS 275.9643, found
79
75.9595; calcd for C10
11 2
H O BrS 273.9663, found 273.9662.
)
2:1) afforded 80 mg (65%) of 4a a .
The following compounds were prepared similarly. The details
(
i) ((2-Iod o-3-m eth yl-2-bu ten yl)su lfon yl)ben zen e (4d a ).
Using 3d (36 mg, 0.17 mmol) and NaI (80 mg, 0.53 mmol)
afforded 43 mg (74%) of 4d a : solid; mp 85-86 °C (dichlo-
of reactions under conditions A are listed below.
b) 2-Br om o-3-(m eth ylsu lfon yl)-1-p r op en e (4a b). Using
(
1
romethane/petroleum ether); H NMR δ 7.87 (d, J ) 7 Hz, 2H),
3
8
5
2
a (60 mg, 0.51 mmol) and LiBr‚H O (104 mg, 1 mmol) afforded
7
(
1
.65 (t, J ) 7 Hz, 1H), 7.54 (t, J ) 7 Hz, 2H), 4.37 (s, 2H), 1.91
0 mg (79%) of 4a b:18 liquid; H NMR δ 6.12 (d, J ) 2 Hz, 1H),
1
+
s, 3H), 1.65 (s, 3H); MS m/ s 336 (M , 12.74), 209 (100); IR (neat)
.94 (d, J ) 2 Hz, 1H), 4.09 (s, 2H), 3.04 (s, 3H); MS m/e 201
-
1
13 2
616, 1308, 1136 cm ; HRMS calcd for C11H O IS 335.9680,
+
81
+
79
(M
+ 1 ( Br), 31.42), 199 (M + 1 ( Br), 31.55), 119 (100); IR
found 335.9687.
-
1
(neat) 1622, 1304, 1128 cm
.
Rea ction of 3a w ith Na I in DOAc. Syn th esis of 3-Deu -
ter io-2-iod o-3-(m eth ylsu lfon yl)-1-p r op en e (4a a ′). Using 3a
(118 mg, 1 mmol), NaI (300 mg, 2 mmol), and DOAc (1 mL)
(
c) 2-Ch lor o-3-(m eth ylsu lfon yl)-1-p r op en e (4a c). Using
O (60 mg, 1 mmol) afforded
3
2
5
(
6
a (25 mg, 0.21 mmol) and LiCl‚H
2
1
7.2 mg (83%) of 4a c: liquid; H NMR δ 5.66 (d, J ) 2 Hz, 1H),
1
afforded 191 mg (77%) of 4a a ′: liquid; H NMR δ 6.56 (d, J ) 1
.65 (d, J ) 2 Hz, 1H), 3.96 (s, 2H), 3.02 (s, 3H); MS m/e 157
1
3
+
37
+
37
+
35
Hz, 1H), 6.24 (d, J ) 1 Hz, 1H), 4.10 (s, 1H), 2.99 (s, 3H);
C
M
+ 1( Cl), 2.42), 156 (M ( Cl), 1.61), 155 (M + 1( Cl),
+
35
NMR δ 136.381, 88.412, 68.009 (t, J D-C ) 21.44 Hz), 41.071.
.71), 154 (M ( Cl), 3.50), 75 (100); IR (neat) 1630, 1306, 1134
-
1
37
cm ; HRMS calcd for C
4
H
7
O
2
ClS 155.9826, found 155.9871;
ClS 153.9855, found 153.9827.
d ) ((2-Iod o-2-p r op en yl)su lfon yl)ben zen e (4ba ). Using 3b
Com p a r ison of Rea ctivities of 3b, 3c, a n d 3d . A solution
of 3b (11.8 mg, 0.1 mmol), 3c (19.4 mg, 0.1 mmol), 3d (20.8 mg,
0.1 mmol), and NaI (15 mg, 0.1 mmol) in HOAc (1.5 mL) was
3
5
4 7 2
calcd for C H O
(
1
(36 mg, 0.2 mmol) and NaI (60 mg, 0.4 mmol) afforded 51 mg
stirred at 85 °C for 4 h. After usual workup, the H NMR
(
82%) of 4b a : solid, mp 90.5-91.5 °C (dichloromethane/
spectrum of the crude product showed 4ba was formed in 69%
yield by NMR. The formations of 4ca and 4d a were not observed.
1
0
1
petroleum ether) (reported: mp 89.5-92 °C); H NMR δ 7.93
(
6
d, J ) 7 Hz, 2H), 7.68 (t, J ) 7 Hz, 1H), 7.58 (t, J ) 7 Hz, 2H),
.27 (q, J ) 2 Hz, 1H), 6.08 (d, J ) 2 Hz, 1H), 4.16 (d, J ) 0.9
Ack n ow led gm en t. Financial support from the Na-
tional Natural Science Foundation of China, Laboratory
of Organometallic Chemistry, Chinese Academy of Sci-
ences, and Shanghai Institute of Organic Chemistry are
greatly appreciated.
+
Hz, 2H); MS m/e 308 (M , 7.40), 77 (100); IR (KBr) 1612, 1306,
1
-
1
134 cm
e) ((2-Br om o-2-p r op en yl)su lfon yl)ben zen e (4bb). Using
b (36 mg, 0.2 mmol) and LiBr‚H O (42 mg, 0.4 mmol) afforded
1 mg (78%) of 4bb: solid, mp 75.5-76.5 °C (dichloromethane/
.
(
3
4
2
1
petroleum ether); H NMR δ 7.93 (d, J ) 6 Hz, 2H), 7.68 (t, J )
6
J ) 2 Hz,1H), 4.13 (s, 2H); MS m/e 263 (M + 1 ( Br), 1.69),
2
Hz, 1H), 7.57 (t, J ) 6 Hz, 2H), 5.82 (d, J ) 2 Hz, 1H), 5.77 (d,
Su p p or tin g In for m a tion Ava ila ble: 1H NMR spectra of
+
81
the compounds 4a c, 4bb, 4ca , 4cb, 4d a , and 4a a ′ as well as
+
79
61 (M + 1 ( Br), 1.68), 77 (100); IR (KBr) 1624, 1306, 1134
13
C NMR spectrum of the compound 4a a ′ (8 pages). See any
-
1
79
9 9 2
cm ; HRMS calcd for C H O BrS 259.9507, found 259.9542.
current masthead page for ordering and Internet access
information.
(18) Makosza, M.; J onczyk, A. Pol. Pat.103194, 1979; Chem. Abstr.
1
980, 92, 163616u.
J O981592V