DE1205548B - Process for the production of aminal esters - Google Patents

Description

Process for Making Aminal Esters One older proposal concerns a process for the preparation of N-substituted amidinium salts by reaction of acid amide dialkyl sulfate complex compounds with dialkyl amines.

It has now been found that N, N, N ', N'-tetraalkyl amidinium alkyl sulfates can be converted into aminal esters of the general formula by reaction with alcoholates in which R is an alkyl radical, can convert. In connection with the earlier proposal mentioned above, these aminal esters can also be prepared directly from acid amide dialkyl sulfate complex compounds without isolation of the amidinium salt. So z. B. the complex compound of dimethylformamide and dimethyl sulfate after reaction with dimethylamine and further reaction with alcoholates directly to bis-dimethylaminoalkoxymethane.

These readily available new aminal esters are extremely reactive Compounds and serve as intermediates in the manufacture of cyanines and pharmaceuticals.

Example 1 bis-dimethylamino-methoxy-methane 21.2 g (0.1 mol) of N, N, N ', N'-tetramethyl-formamidinium methyl sulfate is added dropwise with stirring to a suspension of 6 g (0.11 mol) of sodium methylate in Ether, heated to the boil for a short time and distilled. Yield: 10 g (76% of theory); Bp "o = 128 ° C. Example 2 In a suspension of 20 g (0.1 mol) of the dimethylformamide-dimethyl sulfate complex 6.75 g (0.15 mol) of dimethylamine are passed into ether, heated to the boil and added dropwise the reaction mixture with stirring to 6 g of sodium methylate in ether. One heated to the Simmer and distilled. Yield: 9 g (68% of theory); Bp 74o = 128'C. example 3 bis-dimethyamino-ethoxymethane 21.2 g (0.1 mol) of N, N, N ', N'-tetramethyl-formamidinium methyl sulfate is added dropwise with stirring to 7.5 g (0.11 mol) of sodium ethylate in ether, heated to Simmer and distilled. Yield: 11 g (770% of theory); Bp 74o = 136 ° C.

Example 4 Bis-dimethylamino-isopropoxy-methane 106 g (0.5 mol) of tetramethyl-formamidinium methyl sulfate are stirred in 20 minutes to 41 g (0.5 mol) of sodium isopropoxide in 500 ccm dripped with absolute ether and heated to boiling for 2 hours. It is then filtered and the ethereal layer is fractionated. Yield: 52 g (65% of theory); KP. " = 38 to 42 ° C; Bp "0 = 151 to 154 ° C.

Example 5 Bis-dimethylamino-ethoxy-methane 106 g (0.5 mol) of tetramethyl-formamidinium methyl sulfate are stirred for 20 minutes to 42 g (0.5 mol) of potassium ethylate in 500 ccm dripped with absolute ether and heated to boiling for another 2 hours. It is then filtered and the ethereal layer fractionated on a column. Yield: 49 g (67% of Theory); Bp 7ss = 136 to 140 ° C. Example 6 bis-dimethylamino-tert-butoxy-methane 106 g (0.5 mol) of tetramethylformamidinium methyl sulfate are added within a quarter of an hour added dropwise with stirring to 56 potassium tert-butoxide in 180 ccm ether, another 1 hour heated to boiling and filtered. Then the ethereal layer is fractionated in a vacuum. Yield: 54 g (62% of theory); Bp "= 58 to 62 ° C; bp 7QO = 155 to 158 ° C.

Example 7 Dimethylamino-diethylamino-methoxy-methane 75g (0.3 mol) N, N-dimethyl-N ', N'-diethyl formamidinium methyl sulfate are added to 18 with stirring g (0.33 mol) of sodium methylate are added dropwise to 300 cc of ether and boil for 2 hours heated. It is then filtered and the ethereal solution fractionated. Yield: 34 g (71% of theory); Bp "o = 155 ° C.

Claims (2)

Claims: 1. Process for the preparation of aminal esters of the general formula in which R denotes an alkyl radical, characterized in that N, N, N ', N'-tetraalkyl amidinium alkyl sulfates are reacted with alcoholates. 2. Modification of the method according to claim 1, characterized in that that amidinium salts are obtained by reacting acid amide-dialkyl sulfate complex compounds with dialkylamines, without isolation in situ with alcoholates implements.