Sulfuric Acid → 2,2,3,4,4-Pentafluoro-4-[1,1,2,2,3,3-hexafluoro-3-(trifluoromethoxy)propoxy]butanoic acid

2.4 mL water, 8 ml MeCN, 0.16 g KBr, TEMPO (0.06 g), and 5 g of 2,2,3,4,4-pentafluoro-4-(1,1,2,2,3,3-hexafluoro-3-trifluoromethoxy-propoxy)-butan-1-ol (prepared according to Zh. Vses. Khim. Ova, 1979, p 656) were placed in a 50 mL glass flask equipped with a dropping funnel and stirrer. 24 ml 15% (wt.) aq. NaOCl buffered to pH 8-9 were added via the dropping funnel in 3 portions over two days while stirring at room temperature. Then concentrated sulphuric acid and water were added to make the reaction mixture acidic (pH=1-2). The reaction mixture was extracted three times with diethyl ether and the combined ether phases were dried over magnesium sulphate. The solvent was evaporated to give a colorless liquid, which was distilled using a water pump (15 mmHg, 75° C.) to give 4.17 g of the acid. Yield: 81%. 1H NMR (CDCl3): 5.2 (dm, J=43 Hz, 1H); 10.2 (s, 1H); 19F NMR (CDCl3): −56.3 (t, J=8.3 Hz, 3F); −78.5 (m, 2F); −84.7 (m, 2F); −86.87 (m, 2F); −130.45 (m, 2F); −117.9 (AB system, J=277 Hz, 1F); −121.6 (AB system, J=277 Hz, 1F); −130.5 (m, 2F); −214.1 (dm, J=43 Hz, J=ca. 11 Hz, 1F).

1. customequipped with a dropping funnel and stirrer
2. additionwere added via the dropping funnel in 3 portions over two days
3. extractionThe reaction mixture was extracted three times with diethyl ether
4. dry with materialthe combined ether phases were dried over magnesium sulphate
5. customThe solvent was evaporated
6. customto give a colorless liquid, which
7. distillationwas distilled
8. customa water pump (15 mmHg, 75° C.)

ORD record

ord-f9f7d05a96ed470f8b0a01d843a19bac

Source dataset

uspto-grants-2014_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08809580B2