SULPHONAL, Diethylsulphone Dimethyl / SO2C211‘ methane \C , was discovered by CH, \ Baumann in 1886, and introduced into medicine as an active hypnotic in It is prepared by the condensation of a mixture of ethylmercaptan and acetone in the presence of hydrochloric acid or zinc chloride. Under these conditions dimethyl diethyl mercaptole, CH, / is obtained, which yields sulpho \ nal upon oridation with potassium permanganate_ On account of the difficulty experienced in handling ethyl mercaptan, the use of sodium thiosulphon ate C2H•S.S020Na, in the presence of hydro chloric acid, has been suggested. This com pound will also yield a mercaptole with acetone, and from mercaptole sulphonal may be obtained by oxidation.
Sulphonal crystallizes in colorless prisms, It melts at — 126° C., and boils without de composition at C. It dissolves in 15 parts
of boiling water, and in 500 parts of water at 15° C., but is freely soluble in boiling chloro form, alcohol, acetone, benzene and toluene. In doses of 15-30 grains sulphonal will usually induce sleep, although the time required for its action shows wide individual variations. It has been classed among the safe and depend able hypnotics, as it induces quiet sleep with i no marked after-effects, but its continued use has in some instances developed chronic poisoning with fatal consequences.
The hypnotic action of sulphonal has been traced to the ethyl groups present in its molecular structure. It has been. definitely shown that of the compounds closely related to sulphonal those containing no ethyl groups are not physiologically active. Thus ciirnethyl