Note: Descriptions are shown in the official language in which they were submitted.
37~
', .
PROCE55 FOR PREPARING ANTHRAQUINONE5 B4X15
!
Back~round of the Invention
Anthraquinone is one of the most valuable intermediates in the manu-
¦ facture of dyestuffs. Anthraquinones comprise a greater number of dyes having
outstanding fastness properties than any other group of dyes.
ll Anthraquinone is manufactured from phthalic anhydride and dry benzene
¦¦us;ng a large amount of anhydrous aluminum chloride. The process involves the
¦l use of an excess of benzene that must be recovere~i and the treatment of the
hydrogen chloride and aluminum hydroxide produced.
il Pure anthra~uinone can be nlanufactured by the reaction of 1,4-naph-
ll thaquinone with a small excess of 1,3-butadiene at 100-110C in an autoclave
,I followed by air oxidation of the resultant tetrahydroanthraquinone in the
I presence of base. (Ger. Offen. 2,460~922, July 3, 1975, K. Sakuma, H. Arioka, ¦
il T. Kume, Nippon Steel Chemical Co., Ltd.).
,¦ Anthraquinone can also be prepared by the direct reaction of 1,3-
! butadiene with a mixture of naphthalene, phthalic anhydride and 1,4-naphtha-
l quinone that results from the vapor phase oxidation of naphthalene (ll.S.
i Patents No.'s 2,652,408; 2,938,913; and 2,536,833).
! Brief Description of the Inventlon
I ~
It has now been discovered that anthraquinones can be obtained in
¦ good yield in a one step process by reacting 1,4-naphthaquinone and 1,3-
¦ butadiene, which may be substituted, in the presence of a transition metal .
catalys~, and preferably phthalic acid.
More par~icularly, 1,3-butadiene may be substituted with halogens
such as chloro ~nd bromo, 2 to 4 carbon acyl such as acetyl, propionyl and
- ~26937~ - I
n-butyryl~ 1 to 3 carbon alkyl such as methyl, ethyl and isopropyl; and
hydrogen. The substitution can be in the 1 or 2 posit;on. Representative
examples of substituted butadienes include
1-acetoxy-1,3-butadiene;
2-acetoxy-1,3-butadiene;
1 1-chloro-1,3-butadiene;
i 2-chloro-1,3-butadiene;
',1 1-methyl-1,3-butadiene;
2-methyl-1,3-butadiene;
1-ethyl-1,3-butadiene;
2-ethyl-1,3-butadiene;
bromo-1,3-butadierle; and
1, 2-bromo-1,3-butadiene.
! The catalyst is a salt of a transition metal such as Cr Mn, Fe, Co,
Ni, Cu and Zn Other transition metals may be used but are less preferred
~¦because of higher cost and limited availability. The anion to form the salt
!¦may be selected from d number of inorganic and or9anic materials to include
¦!chloride, nitrate, carbonate, bicarbonate, sulfate, sulfide, oxide, phthalate,
¦Ibenzoate, naphthallate, toluate and phosphate~ If desired, the salt may be
~formed in situ. While the catalysts containing iron are preferred, the
particular anion employed as well as the cation employed (other than iron) is
not particularly important. The amount of catalyst employed will depend upon
Ithe reactants but generally from about 1 to about 20% by weight of the
'Inaphthaquinone will be sufficient.
'l Depending upon the reactants employed, it may be necessary to use a
lsolvent. Typical solvents are the 1 to 3 carbon alcohols, Typical alcohols
'ilare methanol, ethanol, propanol, and butanol. Other suitable solvents are
¦¦tetrahydrofurane and dioxane.
!l
I :
~ 6937
.
'I
'I . .
¦ For best results, a slight excess of butadiene to naphthaquinone is
,¦employed. Thus, while substantially equimolar amounts may be used, it is
'!preferred that the molar ratio of naphthaquinone to butadiene be 1~ 1.4.
The reaction can be conducted at a temperature between about 80C and
,labout 130C at a pressure between about 3 and about 8 atm. in a period of
,Ibetween about 4 hrs. and about 10 hrs. A preferred temperature range is
j¦bet~een 90C and 110C and a preferred pressure range is between 4 and 6 atm.
The following examples will serv~ to illustrate the invention and
preferred embodiments thereof. All parts and percentages in said examples and
elsewhere in the specification and claims are by weight unless otherwise indi-
cated.
i.l 1
Example 1
Chemically pure 1,4-Naphthaquinone (2.0 9, 0.013 mole), 1,3-butadiene
1(1,Q 9, 0,018 mole) and anhydrous FeC13 (0.20 g, 0.0013 mole) were dissolved
linto 12 ml absolute alcohol and placed in a thick reaction tube (O.D.1/2 ~ 5/8
¦inches, wall 3/32 inches).
Chemically pure naphthaquinone was used as colnrnercial grade naph-
thaquinone contains phthalic anhydride which causes the formakion of anthra-
¦quinone. The tube was cooled to -70C (dry ice-acetone) and evacuated by a
high vacuum pump. The tube was sealed in vacuum and heated at 90 120C for
'i17 hours. The pressure was built up to 4-~ atmospheres during the reactonO
Upon cooling the solution, the solid prec,pitated and was isolated by filtra-
¦tion and washed with dilute aqueous HCl and water. The solid was crystallized
from 95% alcohol as yellow needles (m.p. 285 - 287C) and identified as
Idnthraquinone by l.R. and by mixed melting point. Yield 2.30 9 (û8~).
i
Il l
~Z~93
il
Example 2
The reaction was carried out under the same conditions as described
in Example 1 except that a catalyst was not employed. The white solid
¦produced was filtered and identi~ied as 1,4-dihydro, 9,10-anthraquinone (m.p.
105 - 108C). Yield 2.29 g, (86%).
Il I
Example 3
The reaction was carried out under the same conditions as described
in Example 1 except that equal molar amounts of FeCl3 and phthalic acid were
used. Anthraquinone, (m.p. 284 - 286C) was obtained~ Yield 2.33 g, (90
Example 4
i I
,I The reaction was carried out under the same conditions as described
¦lin Example 1 except that equal molar amounts of NiCl2 and phthalic acid were
jused~ Anthraquinone (m.p. 284 - 286C) was obtained. Yield 1.4 9, (54%). In
~¦addition to anthraquinone, many side-products were obtained and the structures
¦were not identified.
i! l
il Example 5
The reaction was carried out under the same conditions as described
in Example 1 except that equal molar amounts of Ni(NC3)2 and phthalic acid
¦were used. Anthraquinone, (m.p. 284 - 286C) was obtained. Yield 1.5 9,
¦ (56g). Other side products were also obtained.
Example 6
The reaction was carried out under the same conditions as described
l¦in Example 1 except that e~ual molar amounts of Co(Nn3)2 and phthalic acid
I¦ were used. Anthraquinone (m.pO-284 - 2B6C) was isolated. Yield 1.4 g,
!¦ (54~)- Other side products were also obtained.
- 4 -
Example 7
1,4-Naphthaquinone (7.9 9, O.OS mole), 1,3-butadiene (3.5 9, 0.07
mole), Fe(N03)3 (1.0 9, 0.002S mole) and phthalic acid (0.4 9, 0.0025 mole)
llwere dissolved into 60 ml absolute alcohol. The mixture was placed in an
,lautoclave. This was then cooled in dry ice/acetone and degassed.
~I The autoclave was then heated at llQC for 6 hours. The pressure was
built up to 6 atmospheres during the reaction. After the reaction, the con-
jtainer was cooled to room temperature. The volatile gases were analyzed by
!¦mass spectrum and found to be hydrogen and unreacted butadiene.
!I The solid produced was isolated and recrystallized from 95% alcohol
¦(mp. 285 - 287C). The solid was identified as anthraquinone by I.R.
measurement and by mixed meltiny point measurement. YiPld 9.3 y, (89.5%).
1! i
i! Example 8
The reaction was carried out using the same conditions as described
in Example 7 except that Co(N03)2 (0.073 9, 0.0025 mole) instead of FeCl3 was
used as the catalyst. Hydrogen and unreacted butadiene were detected and
anthrdquinrne (m.p. 2ûS - 287C) was obtained. Yield 8.5 9, (87.lX).
Il .
.
~ I 5
