The invention comprises polymeric acetals of aldehydes of the formula OHC-R-CO-CH2CN where R is a divalent heterocyclic or carbocyclic aromatic radical attached to the -CO and OHC-groupings by carbon atoms forming part of the ring system, with a polymeric polyhydric alcohol, such as polyvinyl alcohol. Preferably the polyvinyl alcohol chain contains at least 25 hydroxyl groups per 100 carbon atoms in the chain, between 0.75 per cent. and 10 per cent. of which are acetalized by an aldehyde according to the above general formula and 0.1 per cent. to 5 per cent. are acetalized with an aldehyde containing a sulphonic or carboxylic acid group, e.g. o-sulphobenzaldehyde. Preferably R is a hydrocarbon nucleus such as benzene, or a heterocyclic nucleus containing at least one oxygen, sulphur or nitrogen hetero atom. The acetals are prepared by reacting a monomeric acetal of a cyanoacetylaryl aldehyde (see Group IV (b)), suitably one of the formula where A is the residue of a 1:2 or 1:3 diol, with a hydroxyl polymer containing a large number of recurring -CH2-CHOH-groups. In examples there are prepared the polyvinyl alcohol acetals of (1) 5-cyanoacetyl-2-furaldehyde; (2) 4-cyanoacetylbenzaldehyde; (3) and (4) 2-cyanoacetyl-5-benzofuraldehyde; (5) 2-cyanoacetyl - 3 - methyl - 5 - benzofuraldehyde; (6) 2-cyanoacetyl-3-phenyl-5-benzofuraldehyde and (7) 2-cyanacetyl-3-methyl-naphtho-(2:1-b) furaldehyde. Many other cyanoacetylaryl groups which may be used are specified.ALSO:The invention comprises acetals derived from alcohols and aldehydes of the formula OHC-R.-CO-CH2-CN. where R is a divalent carbocyclic or heterocyclic aromatic nucleus attached to the CHO and CO groups by carbon atoms forming part of the ring system. The alcohol is a monomeric alcohol of 1-4 C atoms or preferably a monomeric 1:2 or 1:3 alkane diol of 2-4 C atoms or it may be a polymeric hydroxy compound (see Group IV (a)). In the latter cases the acetal group has a cyclic structure. The acetals are prepared by reacting the corresponding acetal of a carboalkoxyaryl aldehyde of the formula OHC-R-COOR1 where R1 is an alkyl group of preferably 1-4 carbon atoms with acetonitrile in the presence of alkali, e.g. sodium methylate. In examples there are prepared by the above process the ethylene glycol acetals of (1) 5-cyanoacetyl-2-furaldehyde; (2) 4-cyanoacetyl benzaldehyde; (3) 2-cyanoacetyl-5-benzofuraldehyde and the dimethyl acetals of (4) 2-cyanoacetyl-5-benzofuraldehyde; (5) 2-cyanoacetyl-3-methyl-5-benzofuraldehyde; (6) 2-cyanoacetyl-3-phenyl-5-benzofuraldehyde; and (7) 2-cyanoacetyl-3-methyl-naphtho-(2:1-b) furaldehyde. Many other carbocyclic and heterocyclic nucleii which may be attached to the CO and acetal groups are specified. Acetals of carboalkoxyaryl aldehydes. The acetals derived from carboalkoxyaryl aldehydes of the formula OHC.R.COOR1 described above are prepared by treating the aldehyde with the corresponding alcohol. Specified acetals are the ethylene glycol acetals of 5-carbomethoxy-2-furaldehyde; 4-carbomethoxybenzaldehyde and 2-carbomethoxy-5-benzofuraldehyde and the dimethyl acetals of 2-carbomethoxy-5-benzofuraldehyde; 2-carbomethoxy-3-methyl-5 - benzofuraldehyde; 2 - carbomethoxy - 3 - phenyl - 5 - benzofuraldehyde and 2 - carbo methoxy-3-methyl-naphtho-(2:1-b) furaldehyde. Carboalkoxyaryl aldehydes of the formula OHC.R.COOR1 are prepared by reacting an ester of a halomethylaryl carboxylic acid with 2-nitropropane in the presence of alkali. The aldehydes specified in the above paragraph are prepared in this way. Alkyl esters of halomethylaryl carboxylic acids are prepared by halomethylating an alkyl ester of an aromatic carboxylic acid, specifically by treating the ester with paraformaldehyde in the presence of zinc chloride and dry hydrogen chloride in a chlorinated methane solvent or by brominating a methyl aryl carboxylic ester. Specified halogenated esters are methyl-5-chloromethylfuroate; methyl- 5 -chloromethylbenzofuran-2-carboxylate; methyl-5-chloromethyl-3-methylbenzofuran-2-carboxylate; methyl-5-bromomethyl-3-phenylbenzofuran-2-carboxylate and methyl chloromethyl- 3 -methylnaphtho - (2:1 - b)-furan-2-carboxylate. Methyl-4-bromo-methylbenzoate is prepared by treating p-toluic acid with thionyl chloride, and brominating the resulting p-toluyl chloride and treating with methanol. Benzofuran-2-carboxylic acids. Ethyl 5-methyl-3-phenylbenzofuran-2-carboxylate is prepared by condensing ethyl-a -chlorobenzoyl acetate with p-cresol. Methyl 3-methyl-naphtho-(2:1-b) furan-2-carboxylate is prepared by condensing a -chloroacetoacetate with b -naphthol. The free acid of the former is obtained by hydrolysis.
这项发明涉及配方为OHC-R-CO-CH2CN的醛的聚合物缩醛,其中R是通过环系统的碳原子连接到-CO和OHC基团的二价杂环或碳环芳基,与聚合物多羟基醇(例如聚乙烯醇)反应。最好的聚乙烯醇链中每100个碳原子含有至少25个羟基,其中0.75%至10%的羟基被上述一般公式中的醛缩合,0.1%至5%的羟基被含有磺酸基或羧基的醛缩合,例如邻磺基苯甲醛。最好的R是类似苯的碳氢核或含有至少一个氧、硫或氮杂原子的杂环核。这些缩醛是通过将氰乙酰芳基醛(见IV(b)组)的单体缩醛(例如公式中的A是1:2或1:3二醇的残基)与含有大量重复-CH2-CHOH-基团的羟基聚合物反应制备的。在示例中,制备了(1)5-氰乙酰-2-呋喃醛;(2)4-氰乙酰苯甲醛;(3)和(4)2-氰乙酰-5-苯并呋喃醛;(5)2-氰乙酰-3-甲基-5-苯并呋喃醛;(6)2-氰乙酰-3-苯基-5-苯并呋喃醛和(7)2-氰乙酰-3-甲基-萘-(2:1-b)呋喃醛的聚乙烯醇缩醛。还指定了许多其他可用的氰乙酰芳基。此外,该发明涉及由配方为OHC-R.-CO-CH2-CN的醇和醛衍生的缩醛,其中R是通过环系统的碳原子连接到CHO和CO基团的二价碳环或杂环芳基。醇是1-4个碳原子的单体醇,或者更好地是2-4个碳原子的1:2或1:3烷二醇,或者它可以是聚合羟基化合物(见IV(a)组)。在后一种情况下,缩醛基具有环状结构。这些缩醛是通过将配方为OHC-R-COOR1的羧基烷醛的相应缩醛(其中R1是1-4碳原子的烷基)与碱(例如甲基苏打)存在下乙腈反应制备的。在示例中,通过上述过程制备了(1)5-氰乙酰-2-呋喃醛的乙二醇缩醛;(2)4-氰乙酰苯甲醛的乙二醇缩醛;(3)2-氰乙酰-5-苯并呋喃醛的乙二醇缩醛以及(4)2-氰乙酰-5-苯并呋喃醛的二甲基缩醛;(5)2-氰乙酰-3-甲基-5-苯并呋喃醛的二甲基缩醛;(6)2-氰乙酰-3-苯基-5-苯并呋喃醛的二甲基缩醛;以及(7)2-氰乙酰-3-甲基-萘-(2:1-b)呋喃醛的二甲基缩醛。还指定了许多其他可连接到CO和缩醛基的碳环和杂环核。羧基烷醛的缩醛。通过处理上述配方为OHC.R.COOR1的羧基烷醛制备。指定的缩醛是5-羧甲氧基-2-呋喃醛;4-羧甲氧基苯甲醛和2-羧甲氧基-5-苯并呋喃醛的乙二醇缩醛以及2-羧甲氧基-5-苯并呋喃醛的二甲基缩醛;2-羧甲氧基-3-甲基-5-苯并呋喃醛;2-羧甲氧基-3-苯基-5-苯并呋喃醛和2-羧甲氧基-3-甲基-萘-(2:1-b)呋喃醛。通过将卤代甲基芳基羧酸酯与2-硝基丙烷在碱的存在下反应制备配方中指定的羧基烷醛。上述段落中指定的醛以这种方式制备。通过卤代化芳基酸酯的烷基酯卤代化,具体地通过在氯代甲烷溶剂中用氯化锌和干氯化氢处理酯与多甲醛或溴化甲基芳基酸酯溴化制备。指定的卤代酯是甲基-5-氯甲基呋酸酯;甲基-5-氯甲基苯并呋喃-2-羧酸酯;甲基-5-氯甲基-3-甲基苯并呋喃-2-羧酸酯;甲基-5-溴甲基-3-苯基苯并呋喃-2-羧酸酯和甲基氯甲基-3-甲基萘-(2:1-b)-呋喃-2-羧酸酯。通过用亚砜氯处理对甲苯甲酸,溴化所得的对甲苯基氯化物,然后用甲醇处理制备甲基-4-溴甲基苯甲酸酯。苯并呋喃-2-羧酸。通过将乙酰氯苯甲酸乙酯与对甲酚缩合制备乙基-5-甲基-3-苯基苯并呋喃-2-羧酸酯。通过将α-氯乙酰乙酸酯与β-萘酚缩合制备甲基-3-甲基-萘-(2:1-b)呋喃-2-羧酸酯。前者的游离酸可通过水解获得。