Reaction #51687

Reaction equation

water

phenylhydrazine

dihydro-thiophen-3-one

→

3,4-dihydro-2H-thieno[3,2-b]indole

Yield 48.4%

Solvents

acetic acid

Conditions

Workup

1. 1
   Otheran exothermic reaction
2. 2
   Filtrationthe precipitate was filtered
3. 3
   OtherPurification on a short column of aluminum oxide (activity II, 6% water)

Procedure

To a solution of phenylhydrazine (5.0 g, 46 mmole) in acetic acid (50 ml) was added dihydro-thiophen-3-one (4.72 g, 46 mmole) at room temperature. Following an exothermic reaction, the temperature was maintained at 80° C. for 2 h. The reaction mixture was poured into water (300 ml) and the precipitate was filtered. Purification on a short column of aluminum oxide (activity II, 6% water) using t-butylmethylether as the eluting solvent gave pure 3,4-dihydro-2H-thieno[3,2-b]indole as a yellow solid (3.9 g, 48% yield), m.p. 152-155° C. (lit. m.p. 153° C., WO01/12603) Step 2

Source