Manufacture of haloalkyl lactams

#In one aspect, this invention relates to an improved process for the synthesis of haloalkyl lactams and, in another aspect, to the product obtained in at least 99% purity.

#The haloalkyl lactams of the present invention have diverse uses which include chemical intermediates as quaternizing agents and alkylating agents. As chemical intermediates, they are useful precursors in the synthesis of quarternized lactam products, species of which are disclosed in my co-pending patent application Ser. No. 922,923, filed Oct. 24, 1986, now U.S. Pat. No. 4,732,990 prior methods of preparing the haloalkyl lactams have been relatively time consuming and involve considerable expense, requiring the use of flammable solvents, fractional distillation using 5-10 fractionation trays, followed by tedious purification and recycle steps. Moreover, the product obtained by such prior processes has shown objectionable contamination of methylene bispyrrolidone by-product.

#Accordingly, it is an object of this invention to overcome the above difficulties by an economical and commercially feasible process.

#Having thus generally described the process of the present invention reference is now had to the following examples which illustrate preferred embodiments but which are not to be construed as limiting to the scope of the invention as more broadly set forth in the foreooing disclosure and in the appended claims.

#To a 1 liter round bottom flask equipped with stirrer, nitrogen inlet, condenser, and powder addition funnel was charged, 187.6 g. (1.53 moles) thionyl chloride. To the thionyl chloride, which was cooled to 10.degree. C., 172.5 g. (1.49 moles) N-hydroxymethyl-2-pyrrolidone was added over a 2-hour period. The reaction was maintained at 10.degree. to 25.degree. C. during the addition and the reaction mixture was held at 25.degree. C. for 3 hours after the addition is completed. Excess thionyl chloride together with SO.sub.2 and HCl by-product were removed by heating to 60.degree. C. at 125 mm of vacuum. The reaction flask was set for a straight take-off distillation and the remaining liquid product mixture was distilled at 0.25 to 0.4 mm Hg to remove vaporized product which boils at 66.degree. to 70.degree. C. The vaporized product was collected and cooled to room temperature during which the N-chloromethyl-2-pyrrolidone product, having a melting point of 36.degree.-38.degree. C., crystallized. The yield of 2-chloromethyl-2-pyrrolidone, 181 g., was 91% of theory.

#The product was then prepared for anlysis by reacting it with methanol sodium methoxide solution and analysis for chloromethyl pyrrolidone was determined via its methyl ether derivative using gas chromatography with a 5% phenyl methyl silicone capillary column. The N-chloromethyl-2-pyrrolidone product was found to be 100% pure. The product was also analyzed for methylene bispyrrolidone. Analysis showed total absence of this by-product.