Formaldehyde → HCID 53932913, compound

Participants

Reaction Steps

Formaldehyde (0.4 cm3, 40% aqu.soln.) was added to a mixture of indole (0.6 g, 0.005 mol), 2-(piperid-4-yl)-1,2-benzisothiazoline-3-one-1,1-dioxide, hydrochloride (1.5 g, 0.005 mol) and methanol (10 cm3). The mixture was warmed sufficiently to give a clear solution and then allowed to stand without further heating for 2 hours. The clear solution was then evaporated, and the residual water removed by successive evaporation of the residue with ethanol to give a gum. The gum was dissolved in methanol and allowed to stand in ice whereupon the crystalline title compound separated (1.7 g, 79%) as the hydrochloride. Recrystallisation twice from aqueous methanol (80% methanol) gave 1.3 g of the title compound as the hydrochloride hemihydrate, m.p. 214°-215° C.

Provenance & Evidence