# Patent

## Title
Process for the preparation of 3,4-dihydroxybutanoic acid and salts

## Abstract

The dyes are useful for the coloration of textile materials particularly synthetic textiles such as polyester.

## Background
This specification describes an invention which relates to polycyclic dyes.

According to the present invention there is provided a polycyclic dye of the Formula (1): ##STR2## wherein: Ring A is unsubstituted or is substituted by from 1 to 3 groups; (CH.sub.2).sub.p --R.sup.1 or is substituted by from 1 to 4 further groups.

Suitable further substituents for Ring B are preferably selected from --OH, halogen, nitro, alkyl, alkoxy, alkenyl, aryl, alkoxyalkyl, alkoxyalkoxy, alkoxycarbonylalkoxy, alkoxyalkoxycarbonylalkoxy, alkylcarbonyloxyalkoxy, aryloxy, alkylcarbonyl, alkylsulphonyl, CN-alkoxy, HO-alkoxy, HO.sub.2 C-alkoxy, alkylthio, arylthio and --NR.sup.2 R.sup.3 in which R.sup.2 and R.sup.3 are each independently --H, alkyl or alkenyl.

Suitable substituents for Ring A are those listed for Ring B above and --O(CH.sub.2).sub.m (CO.sub.2).sub.n (CH.sub.2).sub.p --R.sup.1 in which m, n, p and R.sup.1 are as hereinbefore defined.

In the substituents for Ring A and Ring B it is preferred that the alkyl or alkoxy parts of the substituents are C.sub.1-4 -alkyl or C.sub.1-4 -alkoxy respectively, the alkenyl is C.sub.3-4 -alkenyl, the aryl is phenyl or naphthyl, and the halogen is --F, --Cl or --Br. Preferred substituents for Ring A are C.sub.1-4 -alkyl, C.sub.1-4 -alkoxy, --NH.sub.2 or --NHC.sub.1-4 -alkyl. Especially preferred substituents for Ring A are C.sub.1-4 -alkyl, C.sub.1-4 -alkoxy, --NH.sub.2 and --NHC.sub.1-4 -alkyl in the 4-position and --H or C.sub.1-4 -alkyl in the 3-position. Where Ring A is substituted by one further substituent it is preferred that this is in the 3-, 4- or 5-position, more preferably in the 4-position. Where Ring A is substituted by two further substituents it is preferred that these are in the 3- and 4-positions, and where there are three further substituents it is preferred that these are in the 3-, 4- and 5-positions. Ring B is preferably unsubstituted, apart from the --O(CH.sub.2).sub.m (CO.sub.2).sub.n (CH.sub.2).sub.p --R.sup.1 group, or is substituted by one or two further substituents and these substituents are preferably in the 3- or in the 3- and 5-positions.

The alkyl or alkoxy substituents suitable for Ring A and Ring B may be straight or branched chain.

The cycloalkyl group represented by R.sup.1 is preferably a C.sub.3-8 -cycloalkyl group, more preferably C.sub.5-7 -cycloalkyl and especially cyclohexyl. The cycloalkyl group represented by R.sup.1 may be substituted by at least one group selected from C.sub.1-6 -alkyl, C.sub.1-6 -alkoxy, hydroxy, cyano, halogen, such as --Cl and --F, nitro, C.sub.1-4 -alkoxy-C.sub.1-4 -alkoxy, C.sub.1-4 -alkylcarbonyl, C.sub.1-4 -alkoxycarbonyl, C.sub.1-4 -alkoxy-C.sub.1-4 -alkoxycarbonyl, C.sub.1-4 -alkylcarbonyloxy, C.sub.1-4 -alkoxycarbonyloxy, C.sub.1-4 -alkoxy-C.sub.1-4 -alkoxycarbonyloxy, phenyl, amino, C.sub.1-4 -alkylamino and di(C.sub.1-4 -alkyl)amino.

A preferred sub-group of compounds of Formula (1) are those in which m is from 1 to 3, n is 1, p is from 1 to 3, and R.sup.1, Ring A and Ring B are as hereinbefore defined. A further preferred sub-group of compounds of Formula (1) are those in which m is from 1 to 3, n is 0, p is from 1 to 3, and R.sup.1, Ring A and Ring B are as hereinbefore defined.

Especially preferred compounds of Formula (1) are those in which R.sup.1 is cyclohexyl, Ring A is unsubstituted or is substituted by C.sub.1-4 -alkoxy, m is 1 or 2, n is 1 and p is from 1 to 3 and those in which R.sup.1 is cyclohexyl, Ring A is unsubstituted or is substituted by C.sub.1-4 -alkoxy, m is from 1 to 3, n is 0 and p is 0.

The compounds of Formula (1) in which n is 1 may be prepared by esterification of the corresponding carboxylic acid to that of Formula I in which --(CH.sub.2).sub.p --R.sup.1 is replaced by H with for example an alcohol of formula HO(CH.sub.2).sub.p --R.sup.1 in which p and R.sup.1 are as hereinbefore defined. The compounds of Formula (1) in which n is 0 may be prepared by alkylation of the corresponding hydroxy compound to that of Formula I in which --(CH.sub.2).sub.m (CO.sub.2).sub.n (CH.sub.2).sub.p --R.sup.1 is replaced by H in an aprotic solvent such as dimethylformamide or sulpholane with an alkylating agent such as a mesylate of formula MeSO.sub.2 O(CH.sub.2).sub.m (CH.sub.2).sub.p --R.sup.1, in which Me is methyl and m, p and R.sup.1 are as hereinbefore defined.

The carboxylic acid and hydroxy compounds referred to above may be prepared by methods described in EP 0033583B and 0146269B and in EP 0363034A.

Compounds of Formula (1) give yellowish-red to bluish-red shades when applied to synthetic fibers or mixtures thereof, especially polyesters by disperse dyeing processes. The compounds of Formula (1) exhibit excellent fastness properties.

The invention is further illustrated by the following examples: cm.sup.3) and sulphuric acid (5 cm.sup.3) was stirred at ambient temperature before filtering off solid material. The solid was washed with water and dried to give 5-hydroxy-2-oxo-3-phenyl-2,3-dihydrobenzofuran (14 g, 65%). 4-carboxymethoxymandelic acid (18 g), acetic acid (100 cm.sup.3) and sulphuric acid (100 cm.sup.3) was heated at 110.degree. C. for 18 hours before cooling. Ammonium persulphate (13.5 g) was added and the mixture heated at 110.degree. C. for 1 hour. The reaction mixture was cooled and poured into a mixture of ice and water, the precipitated solid was filtered off, washed with water and methanol and dried to give 3-phenyl-7-(4-(carboxymethoxy)phenyl)-2,6-dioxo-2,6-dihydrobenzo-[1:2-b, 4:5-b']difuran (10.5 g, 45%). 3-phenyl-7-(4-(carboxymethoxy)phenyl)-2,6-dioxo-2,6-dihydrobenzo-[1:2-b, 4:5-b']difuran (2 g), cyclohexylmethanol (20 cm.sup.3) and sulphuric acid (98%, 0.25 cm.sup.3) was heated at 180.degree. C. for 11/2 hours. The reaction mixture was cooled, the precipitated solid was filtered off, washed with methanol and dried. The dried solid was recrystallised from toluene to give 3-phenyl-7-(4-(cyclohexylmethoxycarbonylmethoxy) phenyl)-2,6-dioxo-2,6-dihydrobenzo-[1:2-b, 4:5-b']difuran (1.6 g, 65%). .lambda..sub.max in dichloromethane=488 nm.

The procedure of Example 1(iii) was followed except that 2-(cyclohexyl)ethanol was used in place of the cyclohexylmethanol. 3-Phenyl-7-(4-(2-cyclohexylethoxycarbonylmethoxy)phenyl)-2,6-dioxo-2,6-dih ydrobenzo-[1:2-b, 4:5-b']difuran (2 g, 79%) was obtained. .lambda..sub.max in dichloromethane=484 nm.

The procedure of Example 1(iii) was followed except that 3-(cyclohexyl)propanol was used in place of the cyclohexylmethanol. 3-Phenyl-7-(4-(3-cyclohexylpropoxycarbonylmethoxy)phenyl)-2,6-dioxo-2,6-di hydrobenzo-[1:2-b, 4:5-b']difuran (1.8 g, 69%) was obtained. A .lambda..sub.max in dichloromethane=484 nm. 4-(n-propoxy)mandelic acid was used in place of mandelic acid. 5-Hydroxy-2-oxo-3-(4-n-propoxyphenyl)-2,3-dihydrobenzofuran was obtained. 4-(n-propoxy)mandelic acid was used in place of mandelic acid. 5-hydroxy-2-oxo-3-(4-(n-propoxy)phenyl)-2,4-dihydrobenzofuran was used obtained. 5-hydroxy-2-oxo-3-(4-(n-propoxy)phenyl)-2,4-dihydrobenzofuran was used in place of 5-hydroxy-2-oxo-3-phenyl-2,3-dihydrobenzofuran. 3-(4-(n-Propoxy)phenyl)-7-(4-(carboxymethoxy)phenyl)-2,6-dioxo-2,6-dihydro benzo-[1:2-b, 4:5-b']difuran was obtained. 3-(4-(n-propoxy)phenyl)-7-(4-(carboxymethoxy)phenyl)-2,6-dioxo-2,6-dihydro benzo-[1:2-b, 4:5-b']difuran (3 g) was used in place of the 3-phenyl-7-(4-(carboxymethoxy)phenyl)-2,6-dioxo-2,6-dihydrobenzo-[1:2-b, 4:5-b']difuran. 3-(4-(n-Propoxy)phenyl)-7-(4-(cyclohexylmethoxycarbonylmethoxy)phenyl)-2,6 -dioxo-2,6-dihydrobenzo-[1:2-b, 4:5-b']difuran (2 g, 56%) was obtained .lambda..sub.max in dichloromethane=518 nm.

The procedure of Example 4 was followed except that 2-(cyclohexyl)ethanol was used in place of the cyclohexylmethanol. 3-(4-(n-Propoxy)phenyl)-7-(4-(2-cyclohexylethoxycarbonylmethoxy)phenyl)-2, 6-dioxo-2,6-dihydrobenzo-[1:2-b, 4:5-b']difuran (2.1 g, 57%) was obtained. .lambda..sub.max in dichloromethane=519 nm.

The procedure of Example 4 was followed except that 3-(cyclohexyl)propanol was used in place of the cyclohexylmethanol. 3-(4-(n-Propoxy)phenyl)-7-(4-(3-cyclohexylpropoxycarbonylmethoxy) phenyl)-2,6-dioxo-2,6-dihydrobenzo-[1:2-b, 4:5-b']difuran (2.2 g, 58%) was obtained. .lambda..sub.max in dichloromethane=518 nm .

A mixture of 3-phenyl-7-(4-hydroxyphenyl)-2,6-dioxo-2,6-dihydrobenzo-[1:2-b, 4:5-b']dif uran (5 g), potassium carbonate (1.9 g), cyclohexylpropylmesylate (3 g) and sulpholane (100 cm.sup.3) were stirred at ambient temperature before heating at 160.degree. C. for 1/2 hour. The reaction mixture was cooled, water was added and the precipitated solid filtered off, washed with water and dried. The dry solid was dissolved in dichloromethane and the resultant solution was filtered to remove insoluble matter before purification by elution from silica and recrystallising from toluene. 3-Phenyl-7-(4-(3-cyclohexylpropoxy) phenyl)-2,6-dioxo-2,6-dihydrobenzo[1:2-b, 4:5-b']difuran (1.5 g, 22%) was obtained. A .lambda..sub.max in dichloromethane=500 nm.

The procedure of Example 1 was used to prepare the following dyes of Formula (2): ##STR3##                 Formula (2) EXAM- PLE    R.sup.1       R.sup.5   R.sup.6 .lambda. max nm ______________________________________ 8 ##STR4##     OC.sub.2 H.sub.5 H     516 9 ##STR5##     CH.sub.3  H     500 10 ##STR6##     NH.sub.2  H     572 11 ##STR7##     NH.sub.2  CH.sub.3 570 12 ##STR8##     NHC.sub.2 H.sub.5 CH.sub.3 621 13 ##STR9##     OC.sub.2 H.sub.5 CH.sub.3 520 14 ##STR10##    OC.sub.2 H.sub.5 H     513 15 ##STR11##    CH.sub.3  H     498 16 ##STR12##    NH.sub.2  H     571 17 ##STR13##    NHC.sub.2 H.sub.5 CH.sub.3 618 18 ##STR14##    OC.sub.2 H.sub.5 CH.sub.3 519 19 ##STR15##    NH.sub.2  CH.sub.3 567 20 ##STR16##    OC.sub.2 H.sub.5 H     517 21 ##STR17##    CH.sub.3  H     501 22 ##STR18##    NH.sub.2  H     569 23 ##STR19##    NH.sub.2  CH.sub.3 570 24 ##STR20##    NHC.sub.2 H.sub.5 CH.sub.3 619 25 ##STR21##    OC.sub.2 H.sub.5 CH.sub.3 518 ______________________________________ ##STR22##

The procedure of Example 7 was used to prepare the following dyes of Formula (3): ##STR23##                Formula (3) EXAM- PLE    R.sup.1       R.sup.8   R.sup.9 .lambda. max nm ______________________________________ 26 ##STR24##    OC.sub.3 H.sub.7 H     533 27 ##STR25##    H         H     499 28 ##STR26##    CH.sub.3  H     510 29 ##STR27##    NH.sub.2  H     578 30 ##STR28##    NH.sub.2  CH.sub.3 580 31 ##STR29##    H         H     499 32 ##STR30##    OC.sub.3 H.sub.7 H     537 33 ##STR31##    CH.sub.3  H     512 34 ##STR32##    NH.sub.2  H     579 35 ##STR33##    NH.sub.2  CH.sub.3 582 36 ##STR34##    OC.sub.3 H.sub.7 H     539 37 ##STR35##    CH.sub.3  H     512 38 ##STR36##    NH.sub.2  H     580 39 ##STR37##    NH.sub.2  CH.sub.3 581 40 ##STR38##    NHC.sub.2 H.sub.5 CH.sub.3 616 ______________________________________ ##STR39##

## Claims

1. A polycyclic dye of the Formula (1): ##STR40## wherein: Ring B is unsubstituted apart from the --O(CH.sub.2).sub.m (CO.sub.2).sub.n (CH.sub.2).sub.p --R.sup.1 or is substituted by from 1 to 4 further groups selected from the group consisting of --OH, --F, --Cl, --Br, nitro, C.sub.1-4 -aklyl, C.sub.1-4 -alkoxy, C.sub.3-4 -alkenyl, phenyl, naphthyl, C.sub.1-4 -alkoxyC.sub.1-4 alkyl, C.sub.1-4 -alkoxyC.sub.1-4 -alkoxy, C.sub.1-4 -alkoxycarbonylC.sub.1-4 -alkoxy, C.sub.1-4 -alkoxyC.sub.1-4 -alkoxy carbonylC.sub.1-4 -alkoxy, C.sub.1-4 -alkylcarbonyloxyC.sub.1-4 -alkoxy, phenoxy, naphthoxy, C.sub.1-4 -alkylcarbonyl, C.sub.1-4 -alkylsulphonyl, CN--C.sub.1-4 -alkoxy, HO--C.sub.1-4 -alkoxy, HO.sub.2 C--C.sub.1-4 -alkoxy, C.sub.1-4 -alkylthio, phenylthio, naphthylthio and --NR.sup.2 R.sup.3 in which R.sup.2 and R.sup.3 are each independently --H, C.sub.1-4 -alkyl or C.sub.3-4 alkenyl, from any of the substituents defined for Ring B above and the group --O(CH.sub.2).sub.m '(CO.sub.2).sub.n '(CH.sub.2).sub.p '--R.sup.1 in which m' is 0, 1, 2 or 3, n' is 0 or 1, p' is 0, 1, 2 or 3.

2. A polycyclic dye of the Formula (1): ##STR41## wherein: Ring B is unsubstituted apart from the --O(CH.sub.2).sub.m (CO.sub.2).sub.n (CH.sub.2).sub.p --R.sup.1 or is substituted by from 1 to 4 further groups selected from the group consisting of --OH, --F, --Cl, --Br, nitro, C.sub.1-4 -aklyl, C.sub.1-4 -alkoxy, C.sub.3-4 -alkenyl, phenyl, naphthyl, C.sub.1-4 -alkoxyC.sub.1-4 -alkyl, C.sub.1-4 -alkoxyaC.sub.1-4 -alkoxy, C.sub.1-4 -alkoxycarbonylC.sub.1-4 -alkoxy, C.sub.1-4 -alkoxyC.sub.1-4 -alkoxy carbonylC.sub.1-4 -alkoxy, C.sub.1-4 -alkylcarbonyloxyC.sub.1-4 -alkoxy, phenoxy, naphthoxy, C.sub.1-4 -alkylcarbonyl, C.sub.1-4 -alkylsulphonyl, CN--C.sub.1-4 -alkoxy, HO--C.sub.1-4 -alkoxy, HO.sub.2 C--C.sub.1-4 -alkoxy, C.sub.1-4 -alkylthio, phenylthio, naphthylthio and --NR.sup.2 R.sup.3 in which R.sup.2 and R.sup.3 are each independently --H, C.sub.1-4 -alkyl or C.sub.3-4 alkenyl, from any of the substituents defined for Ring B above and the group --O(CH.sub.2).sub.m '(CO.sub.2).sub.n '(CH.sub.2).sub.p '--R.sup.1 in which m' is 0, 1, 2 or 3, n' is 0 or 1, p' is 0, 1, 2 or 3.

3. A polycyclic dye according to claim 1 wherein R.sup.1 is cyclohexyl, Ring A is unsubstituted or is substituted by C.sub.1-4 -alkoxy, m is 1 or 2, n is 1 and p is from 1 to 3.

4. A polycyclic dye of the Formula (1): ##STR42## wherein Ring B is unsubstituted apart from the --O(CH.sub.2).sub.m (CO.sub.2).sub.n)(CH.sub.2).sub.p --R.sup.1 or is substituted by from 1 to 4 further groups selected from the group consisting of --OH, --F, --Cl, --Br, nitro, C.sub.1-4 -aklyl, C.sub.1-4 -alkoxy, C.sub.3-4 -alkenyl, phenyl, naphthyl, C.sub.1-4 -alkoxyC.sub.1-4 -alkyl, C.sub.1-4 -alkoxyaC.sub.1-4 -alkoxy, C.sub.1-4 -alkoxycarbonylC.sub.1-4 -alkoxy, C.sub.1-4 -alkoxy carbonylC.sub.1-4 -alkoxy, C.sub.1-4 -alkylcarbonyloxyC.sub.1-4 -alkoxy, phenoxy, napthoxy, C.sub.1-4 -alkylcarbonyl, C.sub.1-4 -alkylsulphonyl, CN--C.sub.1-4 -alkoxy, HO--C.sub.1-4 -alkoxy, HO.sub.2 C--C.sub.1-4 -alkoxy, C.sub.1-4 -alkylthio, phenylthio, naphthylthio and --NR.sup.2 R.sup.3 in which R.sup.2 and R.sup.3 are each independently --H, C.sub.1-4 -alkyl or C.sub.3-4 -alkenyl,

5. A polycyclic dye according to claims 1 to 2 wherein R.sup.1 is cycloalkyl substituted by at least one group selected from C.sub.1-6 -alkyl, C.sub.1-6 -alkoxy, hydroxy, cyano, --Cl, --F, nitro, C.sub.1-4 -alkoxy-C.sub.1-4 -alkoxy, C.sub.1-4 -alkylcarbonyl, C.sub.1-4 -alkoxycarbonyl, C.sub.1-4 -alkoxy-C.sub.1-4 -alkoxycarbonyl, C.sub.1-4 -alkylcarbonyloxy, C.sub.1-4 -alkoxycarbonyloxy, C.sub.1-4 -alkoxy-C.sub.1-4 -alkoxycarbonyloxy, phenyl, amino, C.sub.1-4 -alkylamino and di(C.sub.1-4 -alkyl)amino.