Methanol → HCID 53443203, compound

A solution of 3-bromopropionic acid 22 (571 mg, 3.73 mmol) and sodium methanethiosulfonate 21 (511 mg, 3.81 mmol) in DMF (5 mL) was stirred under argon at 70° C. After 2 h, t.1.c. (ethyl acetate:methanol, 4:1) indicated the formation of two products (Rf 0.3, 0.6) and the absence of any starting material (Rf 0.2). The reaction mixture was cooled to room temperature, water (10 mL) was added and the resulting mixture extracted with ether (3×20 mL). The organic extracts were combined, washed with brine (30 mL), dried (MgSO4), filtered and concentrated in vacuo. The residue was purified by flash column chromatography (DCM:ether, 3:1 (acetic acid, 0.6%)) to yield 2-carboxyethyl methanethiosulfonate 16 (438 mg, 64%) as a white crystalline solid; m.p. 44-46° C. (ethyl acetate/petrol) [Lit. 44-48° C. m.p., value obtained from Toronto Research Chemicals Inc. website (www.trc-canada.com), nmr spectra assigned using Chemical Concepts SpecInfo]; νmax (thin film) 1716 (st, C═O), 1312, 1130 (S—SO2)cm−1, δH (400 MHz, CDCl3) 2.94 (2H, t, J1,2 6.7Hz, 2 x H-2), 3.36 (3H, s, CH3), 3.38 (2H, t, 2 x H-1); δC (100.6 MHz, CDCl3) δ0.6 (t, C-1), 34.4 (t, C-2), 50.6 (q, CH3), 176.7 (s, C═O); m/z (ES−) 183 (M-H+, 100%). HRMS (ES−) Calcd. For C4H7O4S2 (M-H−) 182.9786.

1. extractionthe resulting mixture extracted with ether (3×20 mL)
2. washwashed with brine (30 mL)
3. dry with materialdried (MgSO4)
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customThe residue was purified by flash column chromatography (DCM:ether, 3:1 (acetic acid, 0.6%))

ORD record

ord-d068b15400b749b9877c3b1d23ffd9ba

Source dataset

uspto-grants-2009_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07572604B2