1,2,3,4,7,8,9,9a-octahydropyrido[1,2-a]pyrazin-6-one;hydrochloride

Conditions: temp:120.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 1-(diphenylmethyl)azetidin-3-one (see Bioorg. Med. Chem. Lett.; 13; 2003; 2191-2194, 1.32 g, 5.6 mmol) and octahydro-6H-pyrido[1,2-a]pyrazin-6-one hydrochloride (see Bioorg. Med. Chem.; 2004; 71-86; 1.30 g, 6.8 mmol), in methanol (10 mL) was added acetic acid (1 mL). The solution was mixed with (polystyrylmethyl) trimethylammonium cyanoborohydride (4.2 mmol/g, 1.67 g, 8.8 mmol) and the mixture was heated for 5 min at 120° C. using microwave single node heating. The resin was filtered off and then the solvent was removed by evaporation. The product was purified by means of silica gel chromatography using a mixture of ammonia saturated methanol (2%) and methylene chloride. There was obtained 0.58 g (28%) of 2-[1-(diphenylmethyl)azetidin-3-yl]octahydro-6H-pyrido[1,2-a]pyrazin-6-one as an oil. 1H NMR (500 MHz, CDCl3): 1.4 (q, 1H), 1.7 (t, 2H), 1.8-2.0 (m, 3H), 2.3-2.4 (m, 1H), 2.4-2.5 (d, 1H), 2.7-2.8 (t, 3H), 3.0 (m, 3H), 3.4-3.6 (m, 3H), 4.5 (s, 1H), 4.6 (d, 1H), 7.2 (m, 2H), 7.3 (m, 4H), 7.4 (m, 4H); LCMS: m/z 376 (M+1)+. heating The resin was filtered off the solvent was removed by evaporation The product was purified by means of silica gel chromatography a mixture of ammonia saturated methanol (2%) and methylene chloride