Carbon Dioxide → 3-Azido-2-heptafluoropropoxytrifluoropropionic acid hydrate

Participants

Reaction Steps

Reaction of 26.0 g (0.40 mole) of sodium azide, 33 g (0.75 mole) of carbon dioxide, and 106 g (0.40 mole) of perfluoro(propyl vinyl ether) in dimethyl sulfoxide was carried out in a 400 ml metal tube at 25°. The reaction mixture was poured into a solution of 250 ml of concentrated sulfuric acid in 900 ml of water. Continuous extraction with ether and evaporation of the extracts afforded 140 g of crude 3-azido-2-heptafluoropropoxytrifluoropropionic acid hydrate. This acid was reacted in a 1 L metal tube under autogenous pressure with 150 g (1.39 moles) of SF4 and 84 g (2.0 moles) of NaF in 80 ml of CFCl2CF2Cl at 80° for 12 hr. Distillation gave 82.9 g (58% overall yield) of 3-azido-2-heptafluoropropoxytrifluoropropionyl fluoride, bp 51°-53° (100 mm, 13.3 kPa). IR (CCl4): 2150 (N3), 1875 (COF), and 1300-1100 cm-1 (CF, C--O). NMR (CCl4): 19 F 26.0 (p, JFF 6 Hz, 1F, COF), -82.0 (t, JFF 7.5 Hz, 3F, CF3), -129.3 (d of p, JFF 20, 6 Hz, 1F, CF), and -130.2 ppm (s, 2F, CF2) with an AB pattern for CF2O at -7417 and -7567 Hz (d of q, JFF 20, 7.5 Hz, 1F) and -8181 and -8332 Hz (q, JFF 7.5 Hz, 1F), and for CF2N3 at -8244 and -8430 Hz (t, JFF 5.5 Hz, 1F) and -8465 and -8651 Hz (t, JFF 6.2 Hz, 1F).

Provenance & Evidence