Preparation of 1,3,5,7 tetraacetamido- and 1,3,5,7-tetraaminoadamantanes

#The present invention relates to a novel process for preparing 1,3,5,7-tetraacetamidoadamantane, which provides an improved route to 1,3,5,7-tetraaminoadamantane. The latter compound is an intermediate useful for preparing the novel explosive 1,3,5,7 tetranitroadamantane, which is the subject of a copending U.S. patent application of Everett E. Gilbert and Gilbert P. Sollott entitled "1,3,5,7 Tetranitroadamantane and Process for Prepariang Same", Ser. No. 196,956, filed Oct. 14, 1980.

#Adamantane is also known by the scientific name of tricyclo [3.3.1.1.sup.3,7 ] decane. Adamantanes containing substitutents in the 1,3,5 and 7 positions, as discussed hereinafter, are represented by the following general formula:

#______________________________________ Compound R ______________________________________ ##STR1## I II III IV V VI H Br I NHCOCH.sub.3 NH.sub.2 NO.sub.2 ______________________________________

#The following examples illustrate specific embodiments of the method of carrying out the process of the present invention.

#In a one liter quartz reaction flask equipped with a condenser and agitator, 1,3,5,7-tetraiodoadamantane (7.7 g=0.012 mole) was stirred briskly in 800 ml of acetonitrile (0.07-0.1% water content) to which 1.0 ml of water had been added. The resulting mixture was photolyzed for 64 hours at approximately 60.degree. C. (ambient temperature) in a Rayonet Photochemical Reactor containing 16 lamps, each lamp approximately 0.03 watt, 1849 angstroms and 2.2 watts, 2537 angstroms (manufacturer's literature-The Southern New England Ultraviolet Co., Middletown, CT). The reaction mixture was filtered to separate the yellowish solids formed, which were then washed with acetonitrile and air-dried. The deep-red acetonitrile filtrate was flash vaporized to remove the acetonitrile. The dark, tarry residue was dissolved in tetrahydrofuran and the pale yellow solids which remained undissolved therein were separated by filtration, washed with tetrahydrofuran solvent and air-dried. The combined solids were dissolved in hot water and the solution was neutralized with aqueous sodium hydroxide and filtered. The filtrate was flash evaporated to dryness. The residue of white solids was washed first with acetone, then with cold water, and finally with acetone and air dried. 2.68 grams of 1,3,5,7-tetraacetamidoadamantane product were thus obtained, corresponding to a yield of 51% of theory based on the tetraiodo starting material.

#The product crystallized from water in the form of needles and analyzed as the tetrahydrate. It showed no melting to 360.degree. C., which agrees with that reported by Stetter and Krause (loc. cit.). Analysis. Calculated for C.sub.18 H.sub.28 N.sub.4 O.sub.4 .4H.sub.2 O: C, 49.53; H, 8.31; N, 12.84; O, 29.32; H.sub.2 O 16.51%; Mol. wt. 436.5. Found. C, 49.97; H, 8.50; N, 12.46; O, 29.33; H.sub.2 O (by weight loss). 16.23%; Mol. wt. (in H.sub.2 O), 421.