反应详情

Sixty grams of 1,3-diaminopentane (96.7% purity, 0.569 mole), 60 g acetonitrile (1.46 moles) and 1 g of wet Raney® nickel (Raney 2800) catalyst were charged to a 300 ml stainless steel autoclave reactor. The mixture was stirred and heated at 90° C. and 500 psig hydrogen pressure for 6 hours. Capillary GC analysis of the cooled product indicated a 36% conversion of 1,3-diaminopentane and 97.4% yield of 2-methyl-4-ethylhexahydropyrimidine. The reactor was recharged with 25 ml (19.5 g) additional acetonitrile and run at 90° C. and 500 psig for 21 hours. Capillary GC analysis of the mixture indicated a 92.1% conversion of 1,3-diaminopentane and 98% yield of 2-methyl-4-ethylhexahydropyrimidine, b.p. 71° C./20 mm Hg. The structure was confirmed by comparison with a mass spectrum of the hexahydropyrimidine obtained by the condensation of 1,3-diaminopentane and acetaldehyde at 50° C.

1. customrun at 90° C.