3-Oxo-azetidine-1-carboxylic acid tert-butyl ester → 3-(7-Fluoro-4-methyl-3-oxo-2,3,4,10-tetrahydro-9-oxa-1,2,4a-triaza-phenanthren-6-ylamino)-azetidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

A solution of 6-amino-7-fluoro-4-methyl-2,10-dihydro-9-oxa-1,2,4a-triaza-phenanthren-3-one (0.100 g, 0.400 mmol) and tert-butyl 3-oxoazetidine-1-carboxylate (0.171 g, 0.999 mmol) in MeOH (10 mL) and HOAc (1 mL) was stirred at rt for 1 h. Sodium cyanoborohydride (0.176 g, 2.80 mmol) was added and the reaction mixture was stirred at rt for 3 h. The reaction mixture was concentrated in vacuo and the residue was purified by column on silica gel (eluting with 0-10% MeOH in DCM to give 3-(7-fluoro-4-methyl-3-oxo-2,3,4,10-tetrahydro-9-oxa-1,2,4a-triaza-phenanthren-6-ylamino)-azetidine-1-carboxylic acid tert-butyl ester (0.115 g, 71%) as a crude gum, which was used directly in the next step. LC/MS (Table 1, Method 3) Rt=1.374 min.; MS m/z: 428 [M+23]+.

Provenance & Evidence