Mannich products have been isolated in good yields with methylene chloride as a C1 unit, instead of formaldehyde. It is evidenced that, contrary to previous understanding, a high pressure procedure is not necessary required and that the methylene bisamines function as intermediates.
BOEHME, H.;BOMKE, U.;DENIS, J. -P., ARCH. PHARM., 1982, 315, N 1, 40-47