tert-Butyl piperazine-1-carboxylate → HCID 20068695, compound

Participants

Reaction Steps

A solution of 4-chloro-7,8-dihydro-2-(1-methylethyl)-6H-thiopyrano[3,2-d]-pyrimidine (from Table I) (2.8 g) and N-tert-butoxycarbonylpiperazine (5.0 g) in isoamyl alcohol (50 ml) was heated at reflux for 1 hour, cooled, filtered and the solvent distilled at reduced pressure. The residue was dissolved in ether, washed with H2O and brine, dried over magnesium sulfate and evaporated in vacuo. To the residue was added trifluoroacetic acid (40 ml) which after 1 hour was distilled at reduced pressure. The residue was treated with ice and excess 10N sodium hydroxide, extracted into CH2Cl2, washed with water and brine and dried over K2CO3. The CH2Cl2 was distilled at reduced pressure and the residue was dissolved in ethanol (30 ml), treated with 10N ethanolic HCl (3 ml) and ether (30 ml) to give the title compound which melts at 256° to 258° C. after recrystallization from 2-propanol-ether.

Provenance & Evidence