dimethyl 2-bromobutanedioate

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

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 1,2-dihydro-2-oxocyclohepta[b]pyrrole-3-carboxylic acid ethyl ester, sodium salt (12.5 g, described in example 1) and 2-bromobutanedioic acid dimethyl ester (14.5 g) in DMF (14.5 g) was heated at 100° C. for 48 hr. The mixture was cooled, diluted with water and extracted with chloroform. The chloroform extract was passed through a column of silica gel. Subsequent elution of the column with chloroform-methanol (97:3) gave 2.0 g of 2-(3-ethoxycarbonyl-1,2-dihydro-2-oxocyclohepta[b]pyrrol-1-yl) butanedioic acid dimethyl ester, nmr (CDCl3) δ1.4 (t, 3H), 3.35 (m, 2H), 3.6 and 3.7 (2s, 6H), 4.4 (q, 2H), 5.6 (t, 1H), 7.45 (m, 4H), 9.05 (d, 1H). The mixture was cooled extracted with chloroform The chloroform extract Subsequent elution of the column with chloroform-methanol (97:3)