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Vol. 77
been expected if a 1,4-butanemercuriniuin salt had The New Insecticide 0,O-Dimethyl Z,Z,Z-Trichlorobeen an intermediate in the reaction. It is unfor1-hydroxyethylphosphonate tunate that 4-methoxycrotylmercuric salt could not BY W.LORENZ,A, HENGLEIN AND G. SCHRADER be found since its geoisomeric configuration should RECEIVEDNOVEMBER 18, 1954 have been ~ignificant.~The only contaminant which can be isolated is 1,4-dichloromercuri-2,:3-diThe condensation of chloral and trialkyl phosmethoxybutane (estimated as 0.5% of theoretical phite' yields 0,O-dialkyl 0-(2,2-dichloroethenyl)yield). phosphate in an interesting reaction with the elimiExperimental? nation of alkyl chloride 4-Chloromercuri-3-methoxy-l-butane . A . Preparation. -TO a solution of 31.8 g. (0.1 mole) of mercuric acetate in 300 ml. of methanol a t 0" was added 16.3 g. (0.3 mole) of 1,3-butadiene in 50 ml. of methanol. After 5 minutes a t this temperature the system gave a negative test for mercuric ion so it was filtered into 100 ml. of 10% aqueous sodium chloride. The precipitated oil was taken up in 100 ml. of chloroform. This extract was twice washed with water and then was evaporated at room temperature leaving 29.1 g. (91%) of product, m.p. 40-44'. This was extracted with 60 ml. of hot methanol leaving 30 mg., m.p. 140-150;. After two hours a t room temperature 90 mg., m.p. 146-156 , was precipitated. The two crops (0.14%) of 1,4-dichloromercuri-2,3-dimethoxybutane, combined and crystallized from 24 ml. of methanol, were thus purified to melt a t 163165'. A mixture melting point with an authentic sample was not depressed. Evaporation of the extract from which the dichloromercurial had been partly removed yielded successive crops of the monochloromercurial, the first and major crop of which melted a t 49.2-50 O (unchanged by crystallization from methanol, 2 ml. per g.). The less-pure crops, as well as the evaporated mother liquor, could be purified by solution in aqueous alkali followed by acidification with gaseous carbon dioxide after 5 hours; the precipitate ultimately was crystallized from methanol, m.p. 49-50". -4nnl. Calcd. for CBHBCIHgO: C , 18.7; H , 2.82. Found: C , 18.9; H , 2.95. B. Ozonization.-A solution of 0.337 g. (0.001 mole) of 4 ~ u Mand 11 I1 Hellman, T ~ i Ji O U R N ~ L ,73,244 (1951). (4) Melting points have heen corrected against reliable standards.
CH3 CH3>P-OCHa
f CC1,CHO
+
0
+ CH3Cl
CHI CH3>!-O-CH=CC12
(1)
I
This new group of phosphoric esters shows high insecticidal activity associated with a high degree of toxicity toward mammals. The condensation of chloral and dimethyl phosphite proceeds quite differently to yield 0,O-dimethyl 2,2,2-trichloro- 1- hydroxyethylphosphonate (11)3.4
CHi>P-OH CHR
f CC1,CHO
+ 0
OH
The ester I1 is a solid readily soluble in water. The determination of its molecular weight revealed that it is present in the bimolecular state.e I t is relatively non-toxic to mammals. The following LD-50 values were found: rat oral 450 mg./kg., rat (male) intraperitoneal7 223 mg./kg., mouse subcutaneous 400 mg./kg., mouse intraperitoneal 500 mg./kg.' 1 0 0 c ~mortality l of houseflies was obtained in 11 minutes a t a concentration of O . O l ~ ~in, 24 niinUtes a t O.OOl%, and in 280 minutes at 0.0001%;,. The ester I1 is relatively stable a t room temperature in aqueous solution. In an alkaline medium, however, a very interesting rearrangement takes place. TABLE I Time, hr.
Alkaline dec. a t room temperature 111. of 0.1 N Dec., NaOH" usedjg. '35
1
152.5 174,5 .'i 178.5 1 183.2 8 192.0 1 equivalent = 19.4
-
9
Dec by boiling in water a t looo' determination of ac'id liberated M I . of 0.1 N Dec., NaOH used/g. 570
78 90 91 94 99 1711. of 0.1 A'
22.3 45.5 63.8 88.5 92.0 NaOH.
11,5 23 . 3 3:; . 0 4 3 .A 47.5
e l al., Chein. Ber., 87, 753 (1924). (2) W. Perkow, K. Ullerich a n d F. R. Meyer, Natiirurissenscha~~elerl. 38, 353 (1952). (3) W. Lorenz, U. S. P a t e n t 2,701,225. (4) This compound has been made available a s a n insecticide in 1952 under t h e code number Bayer L 13/59. I t has been later described b y Barthel, Giang and Hall.5 I t is currently being marketed under t h e trade n a m e Dipterex. (3) W. F. Barthel, P. A. Giang and S. A. Hall, THISJ O U R N A L , 7 6 , 4186 (1954). (6) V. S. Abramow, Dokludy Acad. N a w k . ( V . S . S . K . ) , 73, 487 (1430): J . Geir. Chetn. (L'.S.S.R.), 2 2 , 547 (1952). (7) K. P. DuBois and G. J . Cotter, A.hI.h. Archives of Industrial Hygiene and Occupational Medicine, in press.
(1) W. Perkow,
May 5, 1953
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single bond due to the adjacent >P=O bond in the formula 111 (as it is the case with carboxylic acid amides), it appears improbable'that such a decrease in intensity of the >C==O band occurs. Thus, this region of the spectrum suggests formula I V as the reaction product. In the range of the I€valency vibrations the reaction product has sever'al absorption maxima. The sharp maxima a t 3.51 p and at 3.40 p with a weak shoulder a t 3.33 p are caused by the methyl groups. 'However, the band a t 3.28 p can no longer be assigned to a methyl group. Because of its longer wave length and sharpness this band cannot be an 0-H band. Therefore, it corresponds to t h e C-H valency vibration of the >C=CH group.gs10 Thus, an additional proof is given for formula IV. In the spectra of isomeric 0,O-dialkyl phosphates and 0,O-dialkyl phosphonates, the maxima d t h e >P=O band are i . 8 and 8.1 p , respectively. The $P=O band of the phosphonates dissolved in CS is split into a doublet, whereas in the phosphates the band is slightly displaced toward a shorter wave length while its form is preserved. The )P== 0 band of the reaction product is at '7.8 p, and after dissolving this substance in CS2 it is split into a doublet a t 7.67 and 7.81 p. Therefore, this region of the spectrum is additional evidence for structural formula IV. This rearrangement of 0,O-dimethyl 2,2,2-trichloro-1-hydroxyethylphosphonateis of considerable theoretical interest as it represents the first reported instance of such transformation of a phosphonate t o a phosphate, The phosphoric acid ester IV is considerably more toxic t o rats, mice and houseflies than the phosphonate 11. Thus, the ~ ~ - value$ 5 0 for IV are: rat oral 25 mg./kg., mouse subcutaneous 25 mg./kg.; and the LD-100 values t o the housefly were: contact 0.01 y and oral 0.005 y, as opposed to 0.1 y and 0.03 y,respectively, for 11. Experimental Part 0,O-Dimethyl 2,2,2-Trichloro-l-hydroxyethylphosphonate (11) was prepared following t h e procedures described by lor en^.^ These differ from t h e method later described by Barthel, et ~ l . only , ~ in t h a t a reaction temperature of 120-130' was used, and t h a t t h e product was recrystallized from water. 0,O-Dimethyl @(2,?-Dichloroethenyl) Phosphate (IV) from Ester I1 by Alkaline Treatment.-One hundred and twenty-nine grams (0.5 m o k ) of 0,O-dimethyl 2,2,2-trichloro-1-hydroxyethylphosphonate is dissolved in 500 ml. of water and warmed t o 30". A solution of 20 g. (0.5 mole) of sodium hydroxide in 50 ml. of water is added dropwise with stirring. The temperature rises and 0,O-dimethyl 0-(2,2-dichloroethenyl) phosphate (IV) separates as 't colorless oil. The oil is dissolved in benzene, washed twice with ice-water and then dried with sodium sulfate (sicc.). On fractionating the benzene solution 54 g. of I V having the boiling point 86-87' a t 3 mm. are obtained; jield 58Yc of the theoretical; n Z o1.4541; ~ d2Or 1.423. Anal. Calcd. for CaHrOaClzP: C1, 32.09; OCH3, 28.08. Found: C1,31.34; OCHI, 28.36. FARBEXFABRIKEX BAYERA G. LEVERKUSEN, GERMANY
T& Tomplete-Itegradation of Cafbon-14 Labeled S.wcinic Acid -and Succinic Anhydride by the Schmidt Reaction' BY E 1; P H A R E 5 A \ D L I A R \ \ !.*O\
