摘要:
2-Amino-3,5-di-(halomethyl)-pyrazines of the general formula I ##STR1## where X is either chlorine or bromine, m and n may each be 0, 1, 2 or 3 and R.sup.1 and R.sup.2 are each hydrogen or a protective group or may furthermore be bonded to one another, in particular those compounds of the formula I in which m is 1 and n is 2 and/or R.sup.1 and R.sup.2 together form a phthaloyl radical, are useful intermediates for the pteridine building block of folic acid or folic acid analogs.They are obtained by a method in which a 2-amino-3,5-dimethylpyrazine of the general formula II ##STR2## is treated with a chlorinating or brominating agent and, where R.sup.1 and/or R.sup.2 are protective groups, these are, if desired, eliminated when the chlorination or bromination is complete.
摘要:
The invention relates to the preparation of low-viscosity aqueous dispersions of glycerol esters of long-chain fatty acids by dispersing under mechanical agitation in the aqueous phase, wherein the starting material is constituted by soap-free glycerol esters having a content of less than 2% by weight of free glycerol esters, a content is set of 0.5-6% by weight of alkali soaps of long-chain fatty acids. The dispersions are utilized for the coating of expandable finely divided styrene polymers.
摘要:
A process for the preparation of 1,3-disubstituted 4,5-cis-dicarboxy-2-imidazolidones useful as intermediates in the preparation of Vitamin H (biotin), said intermediates have the general formula ##STR1## in which R is an aliphatic hydrocarbon radical having 1 to 8 carbon atoms, an aralkyl radical or an aromatic hydrocarbon radical, preferably an allyl radical or a benzyl radical, comprising reacting a defined diaminosuccinic acid with phosgene in the presence of an alkali metal hydroxide.
摘要:
Curable polyester molding materials contain a mixture ofA. an ethylenically unsaturated polyester or a vinyl ester possessing an unsaturated terminal group,B. copolymerizable monomers,C. fibrous reinforcing agents,D. powdered fillers,E. organic free radical initiators,F. a viscosity depressant andG. conventional additives.The viscosity depressant is a tertiary or secondary amine which carries a long-chain alkyl or acyl group and a carboxyl group.
摘要:
Impact-resistant modified styrene polymers having the characteristics: molecular weight M.sub.v 150,000 to 170,000; gel content exceeding 22%; degree of swelling of 11.5 to 13.5 and a mean gel particle diameter of 1.7 to 4.5 microns are produced by continuously polymerizing a styrene solution of polybutadiene, possibly in the presence of diluents, by means of a cascade consisting of at least three continuous stirred tank reactors, at rising temperatures and in the presence of organic peroxide initiators. The process steps are carried out as follows:(a) in a first continuous stirred tank reactor, a continuously introduced solution of styrene containing from 8 to 10.5% by weight (referred to the amount of input styrene) of polybutadiene rubber with more than 85% of a cis-1,4-structure, is polymerized in the presence of 1 to 7 m moles of an initiator per kilogram of styrene, where the initiator concentration is based upon a peroxide group or an equivalent amount of such with several peroxide groups having a half-life time exceeding 5 and less than 40 hours at 100.degree. C. (measured in benzene), for a residence time of 0.8 to 1.6 hours with shearing at temperatures of about 110.degree. to 140.degree. C., to a solid content of about 28 to 42% by weight;(b) polymerization proceeds after transfer into one, two or three further agitation vessels at temperatures of about 130.degree. to 160.degree. C., for a total residence time of about 1.0 to 1.8 hours, to a solid content of about 60 to 73% by weight;(c) polymerization proceeds after transfer into a further continuous stirred tank reactor at a temperature of about 150.degree. to 175.degree. C. and a dwell time of about 1.2 to 2.5 hours up to a solid content exceeding 75% by weight and a residual initiator content less than 1% by weight of the original amount; and(d) the substance is rid of volatile components at temperatures less than 260.degree. C. under reduced pressure.
摘要:
Alkanolamine salts of amide acids having the formula: ##STR1## in which the circle represents a single nucleous aromatic ring or a monocyclic or bicyclic aliphatic ring system in each case with 5 or 6 carbon atoms per ring in which R.sup.1 represents an isoalkyl radical with the longest chain of 6 to 8 carbon atoms and a total of 8 to 12 carbon atoms; R.sup.2 represents a radical alkylene-X wherein the alkylene chain is a branched or straight chain and contains 1 to 4 carbon atoms; X represents OR.sup.3, O(C.sub.2 H.sub.4 O).sub.n -R.sup.3, O(C.sub.3 H.sub.6 O).sub.n -R.sup.3, NR.sup.3 R.sup.3, CN, CONH.sub.2, and COOR.sup.3 ; R.sup.3 represents hydrogen or C.sub.1 to C.sub.4 alkyl; n is an integer of 1 to 4; and wherein the carboxyl and carbonamide groups in said formula are bonded to non-olefinic carbon atoms and arranged in adjacent positions. The use of these salts as corrosion inhibitors in aqueous systems is also disclosed.
摘要翻译:具有下式的酰胺酸的烷醇胺盐:其中圆代表单个核芳香环或单环或双环脂族环系,每个环中具有5或6个碳原子,其中R 1表示异烷基, 6至8个碳原子的最长链和总共8至12个碳原子; R2表示其中亚烷基链是支链或直链且含有1至4个碳原子的自由基亚烷基-X; X表示OR 3,O(C 2 H 4 O)n -R 3,O(C 3 H 6 O)n -R 3,NR 3 R 3,CN,CONH 2和COOR 3; R3代表氢或C1至C4烷基; n为1〜4的整数, 并且其中所述式中的羧基和碳酰胺基团与非烯属碳原子键合并排列在相邻位置。 还公开了在水性体系中使用这些盐作为腐蚀抑制剂。
摘要:
Quaternary ammonium compounds of the formula ##STR1## where R.sup.1 and R.sup.2 are identical or different and each is H, halogen, phenyl, alkyl, alkoxy or alkylthio,R.sup.3 is H or alkyl, hydroxyalkyl, cycloalkyl or aralkyl,R.sup.4 and R.sup.5 are identical or different and each is alkyl, phenyl, cycloalkyl or aralkyl orR.sup.4 and R.sup.5 together are a --(CH.sub.2).sub.4 -- bridge, a --(CH.sub.2).sub.5 -- bridge or a --(CH.sub.2).sub.2 --O--(CH.sub.2).sub.2 -- bridge,R.sup.6 is alkyl andX.sup..crclbar. is Cl.sup..crclbar., Br.sup..crclbar., I.sup..crclbar., CH.sub.3 SO.sub.4.sup..crclbar. or C.sub.2 H.sub.5 SO.sub.4.sup..crclbar., a process for their preparation from Mannich bases of the formula ##STR2## and alkylating agents, and the use of these quaternary ammonium compounds as initiators for the photopolymerization of polymerizable mixtures containing olefinically unsaturated compounds, especially for the preparation of aqueous polymer dispersions or polymer solutions.