To a solution of 2.001 g of N-methyl-D-glucamine in 20 ml of water was added 3.194 g of 3-carboxymethyl-5-(2-methylcinnamylidene)rhodanine [prepared as described in Example 1 (35)], and the mixture was heated to dissolve the rhodanine derivative, and then 40 ml of methanol was added to the solution at the same temperature. The mixture was cooled to room temperature and the precipitated crystals were filtered. The resulting crystals were washed with 5 ml of mixture of water and methanol (1:2), and 5 ml of methanol, and dried under reduced pressure to obtain 3.73 g of the titled compound.
