78168-93-1Relevant articles and documents
Production of S-substituted isothioureas
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, (2008/06/13)
A process for the production of an S-substituted isothiourea including the functional group STR1 in which R1 is an alkyl, alkenyl, aryl or aralkyl radical, comprising reacting a thiourea including the functional group STR2 with an alpha-activated etherifying agent of the formula in which X is a halogen atom, A is a direct bond or CH2, and Y is an electron withdrawing group, thereby to produce the ether STR3 and in a second step reacting the ether with a compound of the formula R1 SH. The process is particularly applicable to the production of the known herbicide STR4 from the corresponding thiourea where in the first step chloroacetic acid is used to form the S- carboxymethyl isothiourea which is then interchanged with ethyl mercaptan. Higher overall yields and/or economies are thereby achieved.
Preparation of 1-amino-1,3,5-triazine-2,4(1H, 3H)-diones
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, (2008/06/13)
Herbicidal 1-amino-1,3,5-triazine-2,4(1H, 3H)-diones of the general formula STR1 are obtained in good yields if an N-substituted O-aryl N-chlorocarbonyl carbamate of the general formula STR2 is reacted with an isothiosemicarbazone of the general formula STR3 or hydrohalide thereof, (R1 to R4 in formulae (I) to (III) having the meanings given in the description), at a temperature between 0° and 50° C., in the presence of an acid-binding agent, the open-chain intermediate products formed thereby are then heated (if appropriate without intermediate isolation), in a second stage, to a temperature between 50° and 150° C. and, finally, in a third stage, the 1-alkylideneamino-1,3,5-triazine-2,4(1H, 3H)-dione formed thereby is hydrolyzed (if appropriate again without intermediate isolation) in an acid medium.
