Triphenylphosphine → Diethyl 1-((1-((tert-butoxycarbonyl)amino)cyclopropyl)methyl)-3-iodo-1H-pyrazole-4,5-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of PPh3 (15.52 g, 59.2 mmol) in THF (80.0 mL) cooled to 0° C. was added DIAD (11.50 mL, 59.2 mmol) and the resulting solution stirred at 0° C. for 0.5 h. Intermediate 104C (8.00 g, 23.66 mmol) was added as a solution in THF (20 mL) at 0° C. and stirred at RT for 45 min. A solution of tert-butyl (1-(hydroxymethyl)cyclopropyl)carbamate (5.32 g, 28.4 mmol) in THF (10 mL) at was added at 0° C. and the reaction mixture was allowed to stir at RT for 16 h. The reaction mixture was diluted with water (250 mL) and extracted with EtOAc (2×200 mL). The combined organic layer was washed with brine dried over Na2SO4, filtered and concentrated. The crude product was purified by silica gel chromatography (220 g REDISEP® column, eluting with 20% EtOAc in hexane). Fractions containing the product were combined and evaporated to afford Intermediate 350A as a pale yellow liquid (10 g, 85%). MS(ES): m/z=508 [M+H]+; 1H NMR (400 MHz, chloroform-d) δ ppm 4.45 (s, 2H), 4.41-4.25 (m, 4H), 1.46 (s, 9H), 1.40-1.30 (m, 4H), 1.24 (s, 3H), 1.03-0.94 (m, 2H), 0.90-0.78 (m, 2H).

Provenance & Evidence