of illustration only and are not to be construed as limiting the scope of the invention in any manner 0 76 g of hcl in ether is added to a solution of 2 42 g of n methyl n 39 cyano n 34 imino 2 tetrahydropyranylthio ethyl guanidine in dry ethanol after a reaction time of 40 minutes infra red spectrophotometry indicates the absence of absorptions by the nitrile component and the presence of absorption activity by the addition intermediary the intermediary is precipitated by an ether and the imino 2 mercapto ethyl guanidine is crystallized as hydrochloride by rubbing the imino 2 mercapto ethyl guanidine is then transformed in water by agno 3 into the ag mercaptide derivative of n methyl n 39 cyano n 34 imino 2 mercapto ethyl guanidine as hydrochloride the following are observed ir film 1710 1655 cm 1 1590 1455 1380 1300 two equivalents of hcl in dry ether are added to a solution of 4 26 g of n methyl n 39 cyano imino n 34 2 hydroxy ethyl guanidine in dry methanol after 30 minutes there is no infra red absorption by the nitrile component and the ir absorptions of the addition intermediary are as follows 1670 1630 1580 1565 cm 1 the intermediary is precipitated by an ether and the resulting oil is taken up by methanol the hydrochloride of n methyl n 39 cyano n 34 imino 2 hydroxy ethyl guanidine is crystallized out by rubbing m p 184 u00b0 186 u00b0 c the following are observed ______________________________________ c h n______________________________________calculated 33 61 5 60 31 37found 33 43 5 72 31 25______________________________________ ir nujol 3250 3120 1720 doublet cm 1 1665 1600 doublet 1510 1400 1290 1260 1105 995 950 900 850 doublet 700 3.