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Substituted ureas were prepared by reactions of 1,2-halohydrins with urea and were tested as antimicrobial additives to motor oils.Substituted ureas attract researchers' attention thanks to a set of valuable properties allowing their use in industry, agriculture, and medicine. Substituted ureas are used as insecticides, as plant growth regulators, as effective additives of various purposes to hydrocarbon fuels, oils, and polymeric materials, as drugs, and as dyes [1].Classical synthetic routes to substituted ureas are mostly based on reactions of amines with urea or with isocyanic acid derivatives, or on carbonylation of amino and nitro compounds [1]. These routes are diverse, but many procedures have certain drawbacks restricting their applicability. Development of new procedures is interesting from both scientific and practical viewpoints. In particular, synthesis of substituted ureas by direct reaction of aliphatic and aromatic alcohols with urea has been reported [2, 3]. However, there are no data on reactions of urea with alkoxy-substituted 1,2-halohydrins. These reactions are examined in our study.Previously, we have studied the reactions of alkoxy-and alkylthio-substituted 1,2-chlorohydrins with thiourea in the presence of various acids [4 3 6]. Proceeding with analysis of the reactivity of ureas and thioureas [7], we prepared in this study N-substituted ureas by reactions of 1,2-halohydrins with urea in the presence of a mixture of H 2 SO 4 and CH 3 COOH.The starting 1,2-halohydrins were prepared by reactions of appropriate alcohols with epichlorohydrin in the presence of ZnCl 2 at 65oC [8].The yield of N-substituted ureas containing various functional groups (see table) can be optimized by varying the temperature (from 60 to 115oC), amount of H 2 SO 4 (135 ml), and reaction time (4 38 h).where R 3 H (I), CH 3 OCH 2 (II), C 2 H 5 OCH 2 (III), C 4 H 9 OCH 2 (IV), C 6 H 5 CH 2 OCH 2 (V).By reactions of I with HCHO and (C 2 H 5 ) 3 N, we prepared N-hydroxymethyl-N`-chloroethylurea VI and cyclic urea VII (see table): I 7 g g g g g g 7776 ClCH 2 CH 2 NHCNHCH 2 OH HCHO 7776 (C 2 H 5 The compounds prepared were tested as antimicrobial additives to MS-11 lubricating oil [GOSTs (State Standards) 9.052375 and 9.085375]. The compounds showed a pronounced antimicrobial effect when present in low concentrations (0.531.0%); they are readily soluble in MS-11 oil and do not stimulate corrosion. Compounds VI and VII are more effective than the commercial antimicrobial additive, 8-quinolinol. With VI, the width of the suppression zone is 0.6 31.4 cm for bacteria and 1.0 31.9 cm for fungi. With 8-quinolinol, these parameters are 0.4 3 0.9 and 0.73 0.9 cm, respectively. EXPERIMENTALThe 1 H NMR spectra were recorded on a Bruker spectrometer (300 MHz, internal reference TMS). The