Formaldehyde → HCID 67317184, compound

Participants

Reaction Steps

A solution of compound of Step 7 in dry CH2Cl2/trifluoroacetic acid (8/2 v/v) was stirred at room temperature for 1.5 hours, then evaporated under reduced pressure. MS (ES) C24H26FN5O3 requires 451. Found: 452 (M+H+). The residue was taken in methanol and the solution was treated with 3 equivalents of triethylamine and stirred for 10 minutes. The mixture was acidified with some drops of acetic acid (pH=5) then treated with formaldehyde (3 eq.) and sodium cyanoborohydride. After over night stirring at room temperature, volatiles were removed by rotary evaporation and the resulting residue, dissolved in the minimum amount of MeOH, was applied on cation-exchange resin. The resin was washed with MeOH and the product was eluted with 1 M ammonia in methanol. The pooled fractions were concentrated to dryness under reduced pressure to get 9-{[benzyl(methyl)amino]methyl}-N-(4-fluorobenzyl)-3-hydroxy-8-methyl-4-oxo-6,7,8,9-tetrahydro-4H-pyrazino[1,2-a]pyrimidine-2-carboxamide as a brown oil. MS (ES) C25H28FN5O3 requires 465. Found: 466 (M+H+). The crude compound was dissolved in methanol, treated with 2.5 eq. of 1 N HCl and the solution was stirred overnight under a hydrogen atmosphere in the presence of catalytic 10% Pd/C. Catalyst was then filtered off through celite, and the filtrate was evaporated under reduced pressure to afford title compound as hydrochloric salt. MS (ES) C18H22FN5O3 requires 375. Found: 476 (M+H+).

Provenance & Evidence