[CONTRIBUTION FROM
THE
DXPARTMENT O F CHEMISTRY, DEPAUW UNIVEBSITY]
;1RYLSULFONYIt ESTERS OF NITRO ALCOHOLS J. L. RIEBSOMER' Received November 27, 19.46
Nitrate (1) and phosphate (2) esters of certain aliphatic nitro alcohols have been reported. Organic esters may be obtained by the reaction of the nitro alcohols with organic acids, acid anhydrides, or acid halides. The most extensive series of organic esters was prepared by Tindall (3). In view of the interest in the use of these compounds as plasticizers it seemed worth while to prepare a series of arylsulfonyl esters which might be useful for the same purpose. The appropriate arylsulfonyl chloride was mixed with the nitro alcohol and pyridine was added to react with the hydrogen chloride formed. The following represents a typical reaction: CHI 0 CH3 0
I I
+
CH3CCHzOH
II
ClSC61.15
CiH& A
I
I I
/I II
CHSCCHZOSC6Ha
+
HC1
0 NO2 0 NOz The best yields were obtained with one of the monohydric nitro alcohols. The diols and triols gave less Eatisfactory yields. 2-Nitro-1-butanol gave none of the expected ester with benzenesulfonyl chloride and only a low yield with p-toluenesulfonyl chloride. This behavior can probably be accounted for by the observation made by Schmidt and Rutz (4) that nitro olefins form readily when nitro esters of type (I) are wanned with sodium bicarbonate. H OCOCH3
I I
RC-CR
I I
----NaHCos
+
RC=CR
I
CHaCOOH
I
NO2 H
NO2 H
(1) It is to be noted that the carbon atom attached to the nitro group has a single hydrogen atom attached. The hydrogen atom attached to the carbon bearing the nitro group is activated. In the example under discussion it is possible that the ester (11) was formed, but in the presence of pyridine was transformed into H 0 0
I I
II II
CH3CHSCCHzOSCeH5
NOz
{CsHsN) -'
CHaCHzC=CHs
I
0
NO 2
+
I
C~HSSOH
II
0
(11) 2-nitro-1-butene and benzenesdfonic acid. Present address: Department of Chemistry, University of New Mexico, Albuquerque, New Mexico.
182
183
ESTERS OF NITRO ALCOHOLS
TABLE I ARYLSULFONYL ESTERS OF NITROALCOHOLS ANALYSES COYPOUND
X.P..
'C
YIELD,
%
1 Calc'd %S %N --
Found
-~
1. (CH~)zC(NOz)CHpOSOtCsH4CH~-p 2-Nitroisobutyl p-toluenesulfonate
73-74
76.7
5.38
2. CzHsCH(NOp)CHzOSOzCsH,CHs-p. . . . 2-Nitrobutyl p-toluenesulfonate
52.5-53
20.0
5.18
3. p-CH,CsHBOzOCH&(CH,) (NOz)CHzOSOsCsH4CHj-p . . . . . . . . . . . . . . 2-Nitro-2-methyltrimethylene p-tolu'enesulfonate
98.5-99
4. p-CHaCsHBOpOCHzC(CzHs) (NO*)CHzOSOzCsH4CHs-p . . . . . . . . . . . . . . . 2-Nitro-2-ethyltrimethylene p-toluenesulfonate
12.11 5.13
11.72
- - --
-
48.0
14.43
3.61
-
14.46 3.15
--
68.9
3.53
5. ( ~ - C H J C ~ H ~ S O ~ O&NO:. CHI) .......... 122-123 Tris (p-toluenesulfonoxymethy1)nitromethane
39
2.32
67.9
5.47
7. C~IsS020CHzC(CHI)(N0z)CHzOSOnCsHs.. ............................ 2 -Nitro-2 -met hyltrime t hylene benzenesulfonate
11.72
--
153-154
6. (CHj)&(NO~)CHpOSOzC&I~.. . . . . . . . . . 2,-Nitroisobutyl benzenesulfonate
12.28 5.13
14.42 3.04
13.99
--
56
15.40 2.28
15.66
--12.63 5.44
12.34
- - --114
58.1 3.64
15.60 3.35
-
-- -
15.40
8. C~&S020CHzC(CzHJ (NO,) CH~OSOP CsHs.. ............................ 2-Nitro-2-ethyltrimethylene benzenesultonate
9. (CsH&O,OCH2)aCNOz.. . . . . . . . . . . . . . . . Tris (benzenesulfonoxymethy1)nitromethane
69-69.5
44.2
122-123
28.1
153-154 10. (CH~)zC(NOzCH~OSOpCsH4NHCOCHt-; 2-Nitroisobutyl p-acetamidobenzenesulfonate
45.6
11. [~-CHICONHC~HISOIOCHJZC (CHI)(NOS)............................. 2-Nitro-2-methyltrimethylene p-acetamidobenzenesulfonate
3.63
2.88
16.50 3.26
14.90
--
-
17.90 2.46
16.8
- -- -
198
9.21
8.88
-14.4
8.10
7.93
184
J. L. RIEBSOMER
The relatively low yields with the diols and triols would be expected because of the possibility of the formation of a mixture of esters thus increasing the difficulty of purification. EXPERIMENTAL
I n the general procedure for the preparation of these esters, equivalent quantities of the nitro alcohol and arylsulfonyl chloride were mixed and to this mixture was added slightly more than the equivalent quantity of pyridine. The pyridine was added slowly with stirring to prevent too great a temperature rise. The reaction mixture was warmed over steam for from 5 minutes to one hour depending upon the example involved. After the reaction mixture had cooled, water was added to dissolve any unreacted alcohol and the pyridine hydrochloride. At this stage tha ester usually solidified, and the solid was filtered and washed with more water. The crude products were crystallized from methanol, ethanol, or benzene. A number of variations of the above procedure were tried but with less satisfactory results. Sodium carbonate and sodium hydroxide were used instead of pyridine to remove the hydrogen chloride. The resulting yields were about 20% as compared with yields as high as 76% when pyridine was used. Benzene, chloroform, and xylene were tried as reaction media but in all instances the yields were lowered. Heating above the temperature of a steam-bath likewise reduced the yields. The effect of time of heating was studied carefully in the reaction of 2-nitro-2-methyl-lpropanol and p-tolueneaulfonyl chloride. Keeping all other conditions constant and warming the reactants over steam for the indicated period of time, the yields were as follows: one hour, 76.7%; 2 hours, 68%; 3 hours, 65%; 15 hours, 40%. One typical procedure will be described in detail. Six grams (0.05 mole) of 2-nitro-2methyl-1-propanol, 9.5 g. (0.05 mole) of p-toluenesulfonyl chloride, and 5 ml. of pyridine were mixed in a flask and warmed over steam one hour. After cooling to room temperature, 20 ml. of water was added and the mixture was stirred thoroughly. The ester solidified, was filtered, and washed with cold water. This crude product was crystallized from methanol. Yield, 10.4 grams (76.7%); m.p. 73-74". The compounds prepared, together with the yields, melting points, and analyses, are listed in Table I. ACKNOWLEDGMENT
The author wishes to express his thanks to Commercial Solvents Corporation for assistance in carrying out this work. Thanks are also due Dr. P. J. Baker, Jr. of Commercial Solvents Corporation who suggested this problem. SUMMARY
Eleven arylsulfonyl esters of nitro alcohols have been synthesized. Some of these compounds may be useful plasticizers. GREENCASTLE, IND.
REFERENCES (1) HOFWIMMER, Z . Schiess- u. Sprengstofw., 7,43 (1912); Chem. Zenty., 1, 1956 (1912). (2) VANDERBILT, U. S. Patent 2,177,757 (October 31, 1939). (3) TINDALL, Ind. Eng. Chem., 33, 65 (1941).
(4) SCHMIDT AND RUTZ,Ber., 61,21.42 (1928).
