tert-Butanol → Tert-butyl thieno[2,3-b]pyrazin-6-ylcarbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of thieno[2,3-b]pyrazine-6-carboxylic acid (5.55 mmol, 1 g) and triethylamine (16.65 mmol, 2.321 mL) in t-butanol (15 mL) at 70° C., DPPA (6.10 mmol, 1.320 mL) was added. The dark brown solution was stirred overnight at 85° C. The reaction mixture was evaporated to dryness. Purification by chromatography (0-30% ethyl acetate in heptane) gave tert-butyl thieno[2,3-b]pyrazin-6-ylcarbamate 105 (1.28 g, 92%). NMR (400 MHz, CDCl3) 1.57 (s, 9H), 6.77 (s, 1H), 7.42 (br s, 1H), 8.30 (d, J=2.7 Hz, 1H), 8.48 (d, J=2.7 Hz, 1H).

Provenance & Evidence