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1' 01. 7 3 carbitol, 5 cc. of 28% potassium hydroxide, 3 g. of potassium iodide and 0.025 mole of the organic chlorine compound were added in the order given. shaking after each addition.Alkyl 2,4-Dinitrophenyl Sulfones.-The alkyl 2,4-dinitrophenyl sulfides were converted to the corresponding sulfones hv the permanganate method of Bost. Turner and r\Torton.6 [CONTRIBUTION FROM KAUGATUCK CHEMICAL DIVISION OF UNITED STATES RUBBER Co. ]A general method for the preparation of a series of polymerizable, new 2-vinylthiazoles has been developed. The procedure involves the condensation of a-chloroaldehydes and ketones with a-benzoxythiopropionamide to give the corresponding 2-(a-benzoxyethy1)-thiazoles which are pyrolyzed to yield the vinyl compounds. A 2-isopropenylthiazole was also prepared bv an analogous synthesis.In spite of the current interest in polymerizable vinyl compounds and the ease of synthesis of the thiazole ring, no record has been found of the preparation of 2-vinylthiazoles.A practical process for the synthesis of these compounds has now been developed. A series of 2-(a-benzoxyethy1)-thiazoles was prepared by the general method of Olin and Johnson2 and these, or the corresponding alcohols, a on pyrolysis gave the desired 2-vinylthiazoles. Pyrolysis was accomplished at atmospheric pressure by dropping the liquid benzoates or alcohols through a vertical Pyrex tube filled with alumina and heated to 400-550°.4 Yields of 75% were obtained in the better runs.A synthesis of 2-isopropenyl-4-methylthiazole was also accomplished using similar reactions. In this case the condensation between a-benzoxya-methyl thiopropionamide and chloroacetone yielded directly 25% of the isopropenylthiazole together with 48% of the expected benzoxyisopropylthiazole, subsequent pyrolysis of which proceeded smoothly.The unsaturated thiazoles were characterized by copolymerizing them with b~tadiene.~ A homopolymer of 4-methyl-2-vinylthiazole was also prepared. Experimental 2-(a-Benzoxyethyl) -thiazoles.-These compounds were prepared according to the general procedure of Olin and Johnson' by adding the appropriate chloroaldehyde or ketone to a benzene solution of a-benzoxythio ropionamide.' The reactions were exothermic and slow ad&tions were required for the larger runs. After two hours of reflux, dilute sodium hydroxide was added to neutrality and the organic layer was distilled. Crude yields were nearly quantitative. Yields of distilled products and physical constants are given in Table I. In the initial work with chloroacetal and chloroacetalde-(1) Regarding unsaturated thiazole8 see: (a) E. R. Buchman and E. M. Richardson, T a r s JOURNAL, BT, 396 (1945): (b) G. B. Bachman and L. V. Reisey, ibid., 'lt, 1985 (1949) : ( c ) H. Erlenmeyer, ef ai., Hdo. CMm. Ado, 81, 1142 (1948). See abo derence (IC). (s) O& and Johnson* atteurpted without auecwa the dehydration of 2 -(~-h~d r o r~l e t h y l ) -4 -p h e n y S t~~l e using phosphorus pentoude in b e n e .(4) Recent nark has indicsted that reduced presnvc will pcrmit the use of lower...

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