Formaldehyde → N-[trans-1-benzyl-7-chloro-5-(2-chlorophenyl)-2-oxo-1,2,3,5-tetrahydro-4,1-benzoxazepin-3-ylmethyl]-N-methylglycine

Participants

Reaction Conditions

Reaction Steps

To 0.13 g of ethyl ester of N-[trans-1-benzyl-7-chloro-5-(2-chlorophenyl)-2-oxo-1,2,3,5-tetrahydro-4,1-benzoxazepin-3-ylmethyl]glycine obtained in Example 40 were added 2 ml of formalin and 2 ml of oxalic acid; The mixture was heated at 80° C. for 2 hours. The reaction mixture was concentrated under reduced pressure, and the concentrate was subjected to extraction with ethyl acetate. The organic layer was washed with an aqueous solution of sodium hydrogencarbonate, then with water, followed by drying. The solvent was distilled off under reduced pressure. The residue was dissolved in 6 ml of methanol. To the solution were added 0.2 g of potassium carbonate and 2 ml of water. The mixture was stirred for 2 hours at 60° C. The reaction mixture was concentrated under reduced pressure, to which was added water, followed by extraction with ether. The aqueous layer was acidified to pH 4 with dilute hydrochloric acid, followed by extraction with methylene chloride. The organic layer was washed with water and dried, then the solvent was distilled off under reduced pressure. From the residue was obtained 0.1 g of N-[trans-1-benzyl-7-chloro-5-(2-chlorophenyl)-2-oxo-1,2,3,5-tetrahydro-4,1-benzoxazepin-3-ylmethyl]-N-methylglycine as crystals, m.p. 195°-197° C.

Provenance & Evidence