A treatise on chemistry Volume 3, pt. 5 - Henry Enfield Roscoe, Paperback

• Release Date   5/18/2012
• ISBN-13   9781236172518 | 978-1-236-17251-8
• ISBN   1236172515 | 1-236-17251-5
• Format   Paperback
• Author(s)   Henry Enfield Roscoe
• This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1889 Excerpt: ...or some other reducing agent, pure indigo-blue separates out, the yield of which amounts to 40 per cent. of the acid employed, while 68 per cent. are required by theory. the loss is mainly clue to the formation of isatin (Baeyer). This reaction is employed to fix indigo in calico-printing. potassium xanthate, which was found by H. Caro to be the best reducing agent for the purpose, is printed on the cloth together with caustic soda and the acid, the material being then dried and steamed. Ethyl m-thonitrophenylpropiolate, C6H4 (NO2) C2. CO2. C2H6, crystallizes from ether in large tablets, melting at 60--61. Paranitrophenylpropiolic acid has been prepared by paranitrophenyldibromopropionic acid, which is formed by the combination of bromine with paranitrocinnamic acid.s This substance, however, always yields some of the original paranitrocinnamic acid in addition to the nitrophenylpropiolic acid on treatment with alkalis, the bromine being simply eliminated, and it is therefore better to combine ethyl paranitrocinnamate with bromine and treat the ether in hot alcoholic solution with caustic potash.4 Paranitrophenylpropiolic acid forms a silky, yellow mass or yellow needles, which melt at 198 with evolution of gas and decompose into paranitro-acetylene and carbon dioxide when heated to 140 with water. 1 Baeyer, Ber. Deutsch. Chcm. Ges xiii. 229. 1 See also Miiller, Ann. Chcm. Phamn. ccxii. 143. 1 Drewsen, ibid, ccxii. 150. 4 Miiller, ibid, ccxii. 138. Perkin, Jonrn. Chcm. Soc. 1886, i. 410. Ethyl paranitrophenylpropiolate, CgHNOCCOj. C2H6, crystallizes in long, flat needles, melting at 126. Orthamidophenylpropiolic acid, C0H4(NH2)Cj.CO2H, is obtained by the addition of ferrous sulphate solution to a solution of orthonitrophenylpropiolic acid in an excess of am...