ACETIC ALDEHYDE. 105 



decomposition of ethylidene bromide (p. 46) and sodium 

 ethylate. Clear liquid, boiling at 104. Is converted 

 by oxidation into aldehyde and acetic acid ; by con- 

 centrated hydrochloric acid into ethyl chloride. 



Dichloracetal, CHC1 2 .CH(O.C 2 H 5 ) 2 (colorless liquid, 

 boiling at 180) and trichloracetal CC1 3 .CH(O.C 2 H 5 ) 2 

 (lustrous needles; fusing point, 72; boiling point, 

 230) are formed by the action of chlorine on ethyl 

 alcohol. The former is also produced by the action of 

 chlorine on acetal. 



Monobrpmacetal, CH 2 Br.CH(O.C 2 H 5 ) 2 . Is formed 

 by the action of bromine on acetal. Colorless liquid 

 that boils at 170 without undergoing decomposition. 



Dimethyl-acetal, C 4 H 10 2 = CH 3 .CH j 



contained in crude wood-spirit. Is produced by the 

 action of black oxide of manganese and sulphuric acid 

 on a mixture of ethyl and methyl alcohols; and by 

 heating aldehyde with methyl alcohol to 100. Color- 

 less liquid, boiling at 64. 



Ethylidene oxichloride, C 4 H 8 C1 2 0=(CH 3 .CHC1) 2 O 



(isomeric with the second substitution-product resulting 

 from ethylether, p. 49), is obtained by the action of 

 hydrochloric acid on aldehyde. Colorless liquid, boil- 

 ing at 116-117, which, when heated with water, yields 

 aldehyde and hydrochloric acid. 



Dichloraldehyde, CHCP.CHO. Is obtained by 

 distilling dichloracetal with concentrated sulphuric 

 acid. Colorless liquid, boiling at 88-90. Insoluble 

 in water. When preserved it is gradually transformed 

 into a solid, polymeric substance, which, at 120, is re- 

 converted into the original body. Yields dichloracetic 

 acid by oxidation. 



Trichloraldehyde (Chloral), CCP.CHO. Difficult 

 to prepare directly from aldehyde. Is obtained by 



