GB742342A - Improvements in or relating to isomerization of diaminobutynes - Google Patents

Abstract

The invention comprises new 1 : 4-diamino-1 : 3-butadienes having the general formula <FORM:0742342/IV(a)/1> wherein R1 and R2 together and R5 and R6 together each represent divalent chains forming heterocycles with the nitrogen atoms and R3 and R4 represent hydrogen or hydrocarbon groups, and a method of preparing diamino-butadienes having the above general formula, wherein R1, R2, R5 and R6 may also represent individual hydrocarbon groups, comprising isomerizing a diamino-butyne of the general formula <FORM:0742342/IV(a)/2> the Rs having the above meanings, by treating the diamino-butyne at between 0 DEG and 250 DEG C, with sodium metal, lithium metal or a sodium hydrocarbon, e.g. allyl-, amyl-, cyclohexyl-, benzyl- or phenyl-sodium and, preferably, in the presence of an inert organic solvent. The sodium and lithium metals are normally used in the form of a dispersion in an inert solvent. Isomerization of the higher diamino butynes using these metals is facilitated by the presence of a small amount of a lower diamino-butyne. In examples (1) 1 : 4-bis (dimethylamino)-2-butyne is added to naphtha containing a dispersion of sodium in toluene and the mixture refluxed yielding 1 : 4-bis (dimethylamino)-1 : 3-butadiene; phenyl sodium and finely divided lithium in naphtha are used similarly; (2) 6 : 9 - bis (dimethylamino) - 2 : 2 : 4 : 11 : 13 : 13-hexa methyl-7-tetradecyne is added to a mixture of 1 : 4-bis (dimethylamino)-2-butyne, a toluene dispersion of sodium, and naphtha and heated to yield 1 : 4-bis (dimethylamino)-1 : 4-bis (2 : 4 : 4 - trimethyl - pentyl) - 1 : 3 - butadiene; (3) a sodium dispersion in dioxane is added to a dioxane solution of 1 : 4-dimorpholino - 2 - butyne and on heating 1 : 4 -dimorpholino - 1 : 3 - butadiene is obtained; in like manner 1 : 4 - dipiperidino - and 1 : 4 - dithiamorpholino - 2 - butynes yield 1 : 4 - dipiperidino - and 1 : 4 - dithiamorpholino - 1 : 3-butadienes; (4) 1 : 4 - dipyrrolidino - 2- butyne is employed in the method of (1) to yield 1 : 4-dipyrrolidino - 1 : 3 - butadiene; in like manner, 1 : 4-bis (diethyl amino)-2-butyne yields the corresponding diene; (6) 1 : 4-bis (dibutylamino) - 2 - butyne is reacted as in (2) yielding 1 : 4 - bis (dibutylamino) - 1 : 3 - butadiene; similarly, 1 : 4 - bis (dimethylamino) - 1 : 4 - diisopropyl - 2 - butyne yields the corresponding diene; (8) 4 - morpholino - 1 - dimethylamino-2 - pentyne is treated with a toluene dispersion of sodium in naphtha and yields 4-morpholino - 4 - methyl - 1 - dimethylamino - 1 : 3-similarly 1 - morpholino - 1 - phenyl - 4 - dimethylamino - 2- butyne yields 1-morpholino - 1 - phenyl - 4 - dimethylamino-1 : 3 - butadiene; (9) 1 : 4 - bis (dimethylamino) - 1 : 4 - diphenyl - 2 - butyne in xylene is mixed with a sodium dispersion containing 1 : 4 - bis (dimethylamino) - 2 - butyne and heated to yield 1 : 4-bis (dimethylamino)-1 : 4-diphenyl - 1 : 3 - butadiene; (11) 3 : 6 - bis (dimethylamino) - 2 : 7 - dimethyl - 4 - octyne is added to a mixture of benzyl sodium in toluene and naphtha and heated to yield 3 : 6-bis (dimethylamino) - 2 : 7 - dimethyl - 3 : 5 - octadiene. In a comparative test 1 : 4-bis (dimethylamino) - 2 - butyne is heated with potassium in toluene giving a lower yield of the diene as compared with the present process. The diamino-butadienes may be trans-aminated to other diamino-butadienes by reacting with suitable secondary amines; thus 1 : 4-bis (dimethylamino) - 1 : 3 - butadiene reacted under nitrogen with morpholine yields bis (morpholino) - 1 : 3 - butadiene. The diaminobutadienes react with alcohols and mercaptans to form substances useful as fungicides, insecticides and wetting agents; and with some vinylidene compounds to form cyclic products, e.g. with acrylonitrile to form 1 : 4-diamino-3-cyano - 1 : 2 : 3 : 4 - tetrahydrobenzenes. They also react with hydrogen cyanide to form dinitriles as described in Specification 742,340. Diamino-butynes of the above general formula may be prepared by reacting 2 mols. of appropriate secondary amines and aldehydes with 1 mol. of acetylene in the presence of a heavy metal of the 1st or 2nd Groups of the Periodic Table, especially copper or salts of copper such as cuprous chloride, copper acetate or copper formate, suitably following the procedure of Specification 510,904 using the abovementioned proportions. Alternatively, a propargylamine may be prepared from acetylene, a secondary amine and an aldehyde and then reacted with further quantities of secondary amine and aldehyde which may be the same as or different from those used initially. Thus, 1-morpholino - 1 - methyl - 2 - propyne is prepared from morpholine, acetaldehyde and acetylene and then reacted with formaldehyde and dimethylamine in presence of cuprous chloride yielding 4 - morpholino - 1 - dimethylamino - 2 - pentyne. U.S.A. Specification 2,617,827 also is referred to.