Chloroacetone → 7-Chloro-3-methyl-1-benzothiophene

A mixture of 2-chlorothiophenol (750 μL, 6.6 mmol), chloroacetone (1.1 mL, 13.8 mmol) and K2CO3 (1.8 g, 13 mmol) in acetone (15 mL) was refluxed for 2 h. The mixture was filtered and the solvent evaporated. The crude product was dissolved in chlorobenzene (30 mL) and polyphosphoric acid (PPA, 0.5 g) was added. The resulting mixture was refluxed over night (Plé et al., (1988) J. Heterocyclic Chem. 25, 1271-1272). Additional PPA (0.5 g) was added and the reaction mixture was refluxed for another 7 h. The solvent was decanted from the PPA-residue, the residue was treated with CH2Cl2 and the combined organic extracts were washed with water and dried, and then the solvents were removed by evaporation. The crude product was purified on silica using heptane as eluent, to give the title compound (770 mg, 64% over two steps). 1H NMR (400 MHz, CDCl3) δ ppm 2.44 (d, J=1.20 Hz, 3 H) 7.14 (q, J=1.20 Hz, 1 H) 7.32-7.38 (m, 2 H) 7.60-7.65 (m, 1 H)

1. temperaturewas refluxed for 2 h
2. filtrationThe mixture was filtered
3. customthe solvent evaporated
4. dissolutionThe crude product was dissolved in chlorobenzene (30 mL)
5. additionpolyphosphoric acid (PPA, 0.5 g) was added
6. temperatureThe resulting mixture was refluxed over night (Plé et al., (1988) J. Heterocyclic Chem. 25, 1271-1272)
7. additionAdditional PPA (0.5 g) was added
8. temperaturethe reaction mixture was refluxed for another 7 h
9. customThe solvent was decanted from the PPA-residue
10. additionthe residue was treated with CH2Cl2
11. washthe combined organic extracts were washed with water
12. customdried
13. customthe solvents were removed by evaporation
14. customThe crude product was purified on silica

ORDレコード

ord-1ce1baecdb1f4b33a9eb7a5594d572a3

出典データセット

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US09233946B2