01-21-03 22:36
No 400252
US Patent 3808275
Process for Producing Oximes
Example 1:
Cyclododecanone oxime
Into a 500cc glass reactor provided with a stirrer and a condensor were charged 43.2g of hydroxylamine sulfate as the hemihydrate, 200g of water, 0.1g of sodium alpha stannate, and 91g of cyclododecanone, into which gaseous ammonia was blown at a rate of 160cc/min, and the mixture was subjected to reaction at 98*C. for 2hours while being stirred. During this period of time, the pH values varied as follows:
0min 2.4pH
20min 4.6pH
40min 6.3pH
60min 7.8pH
120min 7.9pH
Crystals were separated from the reaction liquid, washed with water, and dried to obtain 97.5g of crude white cyclododecanone oxime. Analysis of the product with GC gave 1.8% by weight of the original ketone. The washings contained 0.2% hydroxylamine as the freebase. Consequently, it was found that the selectivity from hydroxylamine to oxime was 94.5mol %, the conversion of the ketone was 98.1%, and eventual yield was 99.2mol%
Example 2:
Cyclododecanone oxime
Into a flask provided with a stirrer and a condensor were charged 200g of hydroxylamine solution having composition shown hereunder, 0.2g of sodium alpha stannate, and 46.7g of cyclododecanone, and the mixture was subjected to reaction at 100*C for 2 hours while being neutralized with a 20% aqueous sodium hydroxide solution to maintain the pH at 8.0.
To the reaction mixture containing white solids, was added 300g of benzene to dissolve and extract the solids. The benzene layer was analyzed for cyclododecanone and its oxime, and the aqueous layer for hydroxylamine. The results obtained were as follows:
Conversion of the ketone: 96.8mol%
Oxime selectivity (on reacted ketone): 99.0mol %
Oxime selectivity (on reacted hydroxylamine): 94.8mol %
Conversion of hydroxylamine: 84.0%
Note on Reaction: No further examples were listed as the major components of the reaction procedure were left the same. The largest difference was in the type of tin-containing compound used. Regardless of the type of compound used, such as : Na alpha stannate, Na beta stannate, K meta stannate, and orthostannic acid; the yields mostly remained in the high 90% range, most being closer to quantitative yield.
References:
JACS 78, 530
JACS 81, 475
US patent 2270204
US patent 2820825
US patent 3265733
US patent 3574750
Mellor, Inorganic Chemistry, p 580 (1953)
Kirk-Othmer, Encyclopedia of Chemical Technology, 7, p 764 (1951)
Cmerins, Handbuch der Anorganischen Chemie, nr. 23, p 570-596 (1936)
