Patent GB-789317-A (GB)
Title: Dicarboxy-and dicarbalkoxy-benzanilides and improved linear polyesters therefrom
IPC: C08G63/68
Filed: 1954-11-02
Abstract: The invention comprises a compound represented by the general formula <FORM:0789317/IV (b)/1> wherein R represents a hydrogen atom, an alkyl radical containing from 1 to 10 carbon atoms or an aryl radical of the benzene series containing 6 to 9 carbon atoms.  Such compounds are employed in the preparation of linear polyesters (see Group IV (a)).  In examples: 4 : 41-dicarbethoxy-benzanilide is obtained by reacting ethyl p-amino benzoate with p-carbethoxy-benzoyl chloride in pyridine (1); and by adding p-carbethoxybenzoyl chloride and aqueous caustic soda in portions to a benzene solution of ethyl p-amine benzoate; (2).  The product is recrystallized from alcohol.  Other alkyl esters containing from 1 to 10 carbon atoms in the alkyl radical of 4 : 41-dicarboxybenzanilide can be prepared in a similar manner employing the corresponding alkyl homologues of the reactants employed in the above two examples and the appropriate aryl analogues may be employed to form the aryl esters defined above.  The free acid, 4 : 41 - dicarboxybenzanilide, may be obtained by hydrolysis of the above esters.  Sodium hydrogen titanium butoxide is prepared by reacting titanium butoxide with sodium butoxide in butanol. Specifications 777,215, 777,216 and 777,220, [all in Group IV (a)], are referred to.ALSO:The invention comprises a linear polyester containing the repeating unit <FORM:0789317/IV (a)/1> wherein p represents an integer from 2 to 10 inclusive, and a process of preparing a linear polyester which comprises condensing a compound of the general formula <FORM:0789317/IV (a)/2> wherein R1 and R2 each represents a hydrogen atom, an alkyl radical containing from 1 to 10 carbon atoms or an aryl radical of the benzene series containing from 6 to 9 carbon atoms (see Group IV (b)), with a polymethylene glycol (or ester thereof) of the general formula <FORM:0789317/IV (a)/3> wherein p represents a positive integer from 2 to 10 and R3 and R4 each represents an hydrogen atom or a carboxylic acyl radical containing 2 to 4 carbon atoms, the condensation being carried out in the presence of an ester-interchange catalyst, at elevated temperature in an inert atmosphere and the latter part of the condensation being carried out at a pressure of the inert atmosphere of less than 15 mms. of Hg.  Specific benzanilides mentioned include those in which R1 and R2 in the above formula are methyl, ethyl, isopropyl, sec.-amyl, butyl and hexyl groups.  Small amounts of either or both the 4 : 3- and 3 : 31-isomers of the 4 : 41-dicarboxybenzanilide may be present.  Inert atmospheres may consist of nitrogen, hydrogen or helium.  Part of the polymethylene glycol may be replaced by one or more aliphatic ether glycols (or esters) of the general formula R5O-(R7O)r-R7-OR6 wherein R7 represents an alkylene radical of 2 to 4 carbon atoms, r represents an integer from 1 to 10 and R5 and R6 each represents an hydrogen atom or a carboxylic acyl radical of from 2 to 4 carbon atoms, e.g. diethylene- and tetraethylene glycols and bis-(4-hydroxybutyl) ether. Mixtures of glycols may be used.  The benzanilides may be partially replaced with another dibasic carboxy compound, a dialkyl ester of carbonic acid, an aliphatic dibasic branched chain acid, an aliphatic dibasic ether acid or an aromatic dibasic acid or an alkyl ester thereof, e.g. alkyl esters of succinic, adipic, azelaic, oxalic, glutaric, sebacic, suberic, pimelic, 2-ethyl suberic, 4-isopropyl sebacic, diglycollic, b -oxydipropionic, g -oxydibutyric, p : p1-sulphonyl - dibenzoic, terephthalic, isophthalic, m : p1 - sulphonyl - dibenzoic and p : p1-diphenic acids; also p : p1-dicarboxybenzophenone, 1 : 4 - bis - (p - carboxyphenoxy) - n - butane, 1 : 4 - di - (carboxymethyl) benzene, 4 : 41 - di - (carboxymethyl) biphenyl, 1 : 4-di - carboxyethoxy) benzene, 4 : 41 - di - (carboxyethoxy) biphenyl and bis-(p-carboxyphenylmethyl) ether. Catalysts mentioned include alkali metals and alkaline earth metals and the oxides and alkoxides containing from 1 to 8 carbon atoms, carbonates and borates thereof, lead oxide, cerium oxide, compounds of the general formul  M(Al(OR)4), M(HZn(OR)6), M1(HZr(OR)6)2, MH(Ti(OR)6), M2(Ti(OR)6), M1(HTi(OR)6)2, M1(Ti(OR)6), (RR1R11R111N)2 Ti(OR)6, (RR1R11R111N)H(Ti(OR)6), Ti(OR)4 and PbR4 wherein M represents an alkali metal, M1 represents magnesium, calcium or strontium, R represents an alkyl group of 1 to 6 carbon atoms, R1, R11 and R111 each represent a member of the group consisting of R and an aryl group of the benzene series having from 6 to 9 carbon atoms. Solvents which may optionally be employed include diphenyl, diphenyl ether, tolyl sulphones, chlorinated naphthalene, chlorinated diphenyl and dimethyl sulpholane.  Preferred catalysts are those described in Specification 777,216 and U.S.A. Specification 2,720,507.  In examples: polyesters are obtained by reacting 4 : 41-dicarbethoxy - benzanilide with 1 : 5 - pentanediol (3) and (4); with 1 : 6-hexane diol (5), (6) and (7); with the dibutyl ester of p : p1-sulphonyldibenzoic acid and 1 : 6-hexane diol (8)-(11); with dimethyl terephthalate and 1 : 6-hexane diol (12) with dimethyl terephthalate and 1 : 5-pentane diol (13) and 1 : 4-butane diol (14); with the dibutyl ester of p : p1-sulphonyl dibenzoic acid and 1 : 5-pentane diol (15); or 1 : 5-pentane diol and 1 : 10-decane diol (16); with 1 : 6-hexane diol and diethyl succinate (18)-(20) and with 1 : 6-hexane diol and dimethyl sebacate (21)-(23).  In a similar process 4 : 4-dicarbomethoxy-benzanilide is reacted with 1 : 5-pentane diol, 1 : 3-propylene glycol and p : p1-sulphonyl-dibenzoic acid (17).  The catalysts employed in the examples are the compounds of the formul : NaHTi(OC4H9)6(3, 5, 8-15, 17-23); Na2Ti(OC4H9)6 (4); NaH(Zr(OC4H9)6) (6); ((CH3)4N)H(Ti(OC4H9)6) (7); K(Al(OC2H5)4) (16); and dibutyl tin butoxide (17).  Specifications 777,215 and 777,220 also are referred to.