Patent GB-836567-A (GB)
Title: Mono- and poly-phthalidyl ethers
IPC: C08B31/02
Filed: 1957-04-29
Abstract: The invention comprises mono- and polyphthalidyl ethers of aliphatic polyhydroxy compounds containing at least 3 hydroxyl groups, including saccharidic compounds, and their preparation by reacting phalaldehydic acid with the appropriate polyhydroxy compound in the molar proportions necessary to give a mono- or poly-ether as desired. The reaction may be effected at 15-170 DEG  C. and solvents such as water, acetone or dimethyl-formamide and catalysts such as sulphuric acid, potassium acetate or gluconic acid may be present.  The ethers, which have microbicidal properties, contain the phthalidyl radical in the form <FORM:0836567/IV (b)/1> but open-chain esters of the corresponding o-aldehydo benzoic acid are sometimes formed as by-products.  In examples: (1) glycerol is heated with 3 mols. of phthalaldehydic acid at 130 DEG  C., yielding the tris-phthalidyl ether which is bactericidal towards Staphylococcus aureus; (2) 1:2:6-hexane triol is similarly converted to the tris-ether; (3) pentaerythritol is heated with 4 mols. of phthalaldehydic acid in water yielding the tetra-ether; (4) glucose is reacted as in (3) with 1 or 5 mols. of phthalaldehydic acid yielding the mono-ether and phthalidyl-2:3:4:6-tetra-phthalidyl glucoside respectively; (5) sucrose is similarly reacted with appropriate amounts of the acid to give the mono-, di- and tetra-ethers respectively.  In each case the product is isolated by removing water by warming in vacuo.  The phthalaldehydic acid used is obtained as described in Specification 779,981. Other examples are given describing the preparation of phthalidyl ethers of polyvinyl alcohol, starch and cellulosic compounds (see Group IV (a)) including cotton duck, which is thereby rendered rot-proof (see Group VIII). Specification 836,566 also is referred to.ALSO:The invention comprises mono- and polyphthalidyl ethers of polyvinyl alcohol, polysaccharides such as starch, and of cellulose and cellulose ethers having at least 3 hydroxyl groups, and their manufacture by reacting phthalaldehydic acid with the appropriate polyhydroxy compound in the proportions necessary to give a mono- or poly-phthalidyl ether as desired.  The cellulose may be in the form of cotton duck.  The reaction takes place at 15-170 DEG  C. A solvent such as water, acetone or dimethylformamide and a catalyst such as potassium acetate, gluconic acid or sulphuric acid may be present.  The starch and some forms of cellulose which are not fusible or soluble are preferably contacted with a solution of phthalaldehydic acid in water or other inert solvent to disperse the acid uniformly over the surface of the polyhydroxy compound, which is then heated at 85-160 DEG  C. to form the desired ether product.  In examples: (1) an aqueous solution of polyvinyl alcohol is heated with sufficient phthalaldehydic acid to react with 15% of the hydroxyl groups and the mixture is then allowed to stand for 6 days and a precipitated phthalidyl ether of the polyvinyl alcohol is recovered; (2) a solution of an hydroxy propyl methyl cellulose in dimethyformamide is heated with phthalaldehydic acid in the presence of potassium acetate yielding a gel of the phthalidyl ether of the cellulosic compound; (3) strips of cotton duck saturated with an aqueous or acetic acid solution of phthalaldehydic acid are heated to cause etherification of the hydroxy groups in the cellulose molecules by the phthalaldehydic acid; (4) a mixture of starch, phthalaldehydic acid and water is heated on a steam bath yielding a phthalidyl starch ether which is purified by washing with acetone.  The ethers have antimicrobial properties and the treated duck cloth is rendered rot-proof. Specifications 779,981 and 836,566 are referred to.