ethanesulfonic acid

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (2R,4aR,10bR)-6-(2,6-Dimethoxy-pyridin-3-yl)-9-ethoxy-8-methoxy-1,2,3,4,4a,10b-hexahydro-phenanthridin-2-ol (1.5 g; 3.64 mmol) is dissolved in 9 ml of 4-methyl-2-pentanone. The solution is heated up to 50° C. 312 μl (3.82 mmol) of ethansulfonic acid are added. After crystallisation 3 ml 4-methyl-2-pentanon is added and the suspension is stirred over night. The crystals are filtered off and dried to obtain 1.78 g (94%) of the title compound (m.p.: 216° C.). After crystallisation 3 ml 4-methyl-2-pentanon is added The crystals are filtered off dried