Acetic Anhydride → Alphanitro-6-chloro-3-indoleacrylic acid methylester

Participants

Reaction Steps

A 4-l. battery jar was charged with 641 g (4.23 moles) of 6-chloroindole, 926 g (5.3 moles) of crude (ca. 85% pure) alpha-nitro-beta-ethoxy acrylic acid methylester and 475 g (4.65 moles) of acetic anhydride. The mixture was well stirred at room temperature for 45 hours to give a highly viscous suspension of an orange precipitate. 1.5 l of a mixture of benzene-ether-hexane 1:1:3 was added and the mixture stirred vigorously for 30 minutes. The product was collected by filtration, washed with 1.0 l of the same solvent mixture and dried at room temperature and 16 mmHg to constant weight to afford 600 g (51%) of product as orange crystals, m.p. 159-160°.

Provenance & Evidence