Patent GB-770222-A (GB)
Title: Polybasic aromatic acids and esters
IPC: C07C69/76
Filed: 1954-10-26
Abstract: Fibre-forming polymeric polyesters are prepared by condensation of C1 to C3-alkyl esters of acids of the formula (HOOC)R1CH.CH2XCH.CHR1(COOH) where R1 is a C1 to C4 alkyl radical or hydrogen and X is a symmetrically methylated naphthalene or anthracene radical or a 2:5-dimethyl phenylene or 2:3:5:6-tetramethylphenylene radical, with a glycol of the formula HO(CH2)nOH, where n is 2, 3, 4, 6, 8 or 10, and polymerization of the resulting bis-glycol ester by heating.  Condensation of the alkyl esters with diamines and dimercaptans is also mentioned. Polymers may also be formed by reacting the free acid with dihydric alcohols.  In examples: (2) di-(4-hydroxybutyl) 2:3:5:6 - tetramethylphenylene dipropionate is polymerized by heating to give a fibre-forming resin; (3) resins are prepared by condensing dimethyl 2:3:5:6-tetramethylphenylene dipropionate with hexamethylene decamethylene and trimethylene glycols respectively in the presence of sodium methoxide and the reaction mixture heated to effect polymerization.  The Specification also refers to the condensation of acids of the formula: (HOOC)2R1CCH2XCH2CR1(COOH)2 where R1 and X have the meaning given above, or esters thereof with dihydric alcohols such as ethylene glycol to form thermosetting resins suitable for moulding.  Condensation of these acids with diamines and dimercaptans is also mentioned.ALSO:Tetra-carboxylic esters of the general formula <FORM:0770222/IV(b)/1> where X is a symmetrically methylated naphthalene or anthracene radical, or a 2 : 5-dimethylphenylene or 2 : 3 : 5 : 6-tetramethylphenylene radical, Y is a COOR11 radical, R1 is hydrogen or a C1 to C4 alkyl radical, and R11 is a C1 to C4 alkyl radical are prepared by heating one mol. of a compound of the formula Z-CH2-X-CH2-Z where Z is chlorine, bromine or iodine, with 2 to 2.5 mols. of a metal derivative of a malonic ester or an alkyl malonic ester of the formula MCR1Y(COOR11) where M is sodium or potassium. Halogen compounds specified are bis-chloromethyl-, bis-bromomethyl-, and bis-iodomethyl-durene, bis-chloromethyl -, bisbromomethyl - and bis-iodo methyl-p-xylene and symmetrical bis-chloromethyl hexamethyl naphthalene.  Specified metallo-esters are the sodium derivatives of diethyl malonate, di-n-butyl malonate, di-isobutyl malonate, dimethyl butyl malonate, and the potassium derivatives of dimethyl malonate, di-iso-propyl malonate and diethyl methyl malonate.  The resulting tetracarboxylic esters may be hydrolysed to the corresponding tetracarboxylic acids of the formula <FORM:0770222/IV(b)/2> which may be decarboxylated by heating in an inert atmosphere to 180-340 DEG C. to form dicarboxylic acids of the formula <FORM:0770222/IV(b)/3> which may then be esterified to form the C1 to C4 dialkyl esters. The tetracarboxylic and dicarboxylic esters described above or the corresponding acids may be condensed with a glycol of the formula (CH2)n(OH)2 where n is 2, 3, 4, 6, 8 or 10, such as ethylene glycol, trimethylene glycol, tetramethylene glycol hexamethylene glycol and decamethylene glycol or with diamines or dimercaptans and the condensation products polymerized (see Group IV (a)).  The condensation product with pentamethylene glycol is also mentioned. Examples describe (1A) the preparation of bis-chloro-methyl durene by reacting chloromethyl ethyl ether with durene in the presence of stannic chloride or zinc chloride in chloroform, some mono-chloromethyl durene also being formed, reference is also made to the use of hydrogen chloride and formaldehyde as the chloromethylation agent; (1B) the conversion of bis-chloro-methyl durene into ethyl p-tetramethylxylylenedimalonate by reaction with diethyl sodio-malonate in ethanol; (1C) hydrolysis of the product of (1B) with potassium hydroxide in aqueous ethanol to yield p-tetramethylxylylenedimalonic acid and its decarboxylation; (1D) by heating to 330 DEG  C. under nitrogen to give p-tetramethylphenylenedipropronic acid which is esterified (1E) by reaction with phosphorus pentachloride in chloroform and toluene and the resulting acid chloride reacted with methanol to give dimethyl 2 : 3 : 5 : 6 - tetramethylphenylenedipropionate, which is then heated with tetramethylene glycol; (2) in the presence of sodium methoxide to yield di-4-hydroxybutyl tetramethylphenylene dipropionate; or (3) with hexamethylene, decamethylene or trimethylene glycols.