DD223149A1 - PROCESS FOR PREPARING ALPHA-AMINO-NAPHTHO (2,1-D) THIAZOLE-MONO / DI / OH-SULPHONESEURES - Google Patents

Abstract

A simple process for the preparation of α-amino-naphtho (2,1-d) thiazole mono- / di- / OH-sulfonic acids is described by using readily accessible 2-amino-naphthalene mono- / di- / tri-sulfonic acids. sulfonic acids or 2-amino-OH-sulfonic acids are reacted with Rhodansalzen in the presence of an oxidizing agent in aqueous-alcoholic medium in a "one-pot process".

Description

- A-

Field of application of the invention;

The invention relates to a process for the preparation of sulfonic acid-containing heterocyclic Pünfring 'compounds of the naphthalene series. You know, z.3. be used as intermediates for the preparation of dyes. '·.' '

Characteristic of the known technical solutions

ά-amino-naphtho [2, '1-d Ithiazo! sulfonic acids have hitherto been mentioned as diazo-doping components in two derivatives in DD 113,760; but nothing was reported about their production there.

Object of the invention . , ·

The aim of the invention is to provide a technologically simple process on the basis of readily available starting materials for the production of α-amino-naphtho [2, Td] thiasolmono / di- / OH-sulfonic acids, which in a kind of "sintopfverfahren" products in good quality and good yield and where such precursors are used, where for technological reasons

parts of carcinogenic substances, such as. ß-lTaphthyläjoiin may be present, ^ -.

Presentation of the essence of the invention

The invention has for its object to provide a technologico -gisch simple 'process for the preparation of 2-amino-naphtho [2,1-d] thiazole mono- / di- / ÖH sulfonic acids to create. ,

According to the invention, the object is achieved by using those 2-aminonaphthalenesulfonic acids where, either in the nucleus of the naphthalene ring bearing no amino group, one or more sulfonic acid groups and, optionally, an -OH group are present or where 'are used such ß-aminonaphthalene sulfonic acids which carry in α-position and a sulfonic acid group _to-v the still 5-3teliung have another SuIfonsäuregruppe must- V'.

In this case .also only those starting compounds are used which, due to their multiple content: of hydrophilic groups, for example OH and SO ^ PI groups. and especially because of their technical presentation are considered toxicologically harmless. ·. According to the invention 'the object is achieved in that ß-Affiinb-naphthalirisulfonsäureri, which also contain _: OH groups,''in aqueous alcoholic medium with''HhO-. dansalts) in the presence of an oxidizing agent and aqueous acid. Another erfindungsg'emäßer advantage is that in 7-, turn such ß-amino-naphthalene di- or trisulfonic, where a sulfonic acid is in α-position to the ß-st.ändige η amino group, these in cc-S te " sulfonic acid is eliminated during the ring closure reaction. ', -' · '

In the reaction there is a brief heating of the reaction mixture; on a longer .Kochprozeß can be dispensed with. Ss is sufficient to heat the reaction mixture for 15-20 min, to 6O-65 ⁰ C. The process is very easy to perform and also very time-saving The desired heterocyclic acids are obtained in some cases in very good yields.

applications

Example 1 '

2-amino-naphtho-2,1-d-1-thiazole-6-sulphonic acid

a) Su of a solution of 30 g of potassium thiocyanate in 3OO ml of methanol, 25 g of concentrated hydrochloric acid and 3I> 7 g (0.1 mol) of 2-amino-naphthalene-T, 5-disulionsäure added. A solution of 30 ml of perhydrol in 40 ml of methanol is slowly added dropwise to this suspension at room temperature, and the mixture is then heated to .beta.-65.degree. C. for 30 min. After cooling, the reaction mixture is mixed with aq. Aqueous ammonia solution until it has a slightly alkaline reaction and filtered. From the Piltrat 'the sulfonic acid' with conc. HCl precipitated, filtered off with suction and dried. The yield is 90% of theory

b) Starting from 22.3 g (° »1 mol) of 2-amino-naphthalene-5-sulfonic acid, this sulfonic acid is as in. Example 1a), obtained in a yield of 90 % .

Example 2

2-amino-naphtho Γ2, 1-d "lthiazol-7-sulfonic acid

a) Starting from 22.3 g (0.1 mol) of 2-amino-naphthaiin-. ö-sulfonic acid is the desired heterocyclic 'sulfonic acid, analogously as described in Example 1,

. '"· - ⁴ - '· ·

obtained in a yield of 85%. , .. b) From .31,7. g (0.1 mol) of 2-amino-naphthalene-1,6-disulfonic ¹ sulfonic acid the Thiazolsulfonsäure, as in the example "1..beschrieben, · in a yield of 85% is obtained.

Example 3 , '..-'

2-amino-naphtho [2,1-d] thiazole-9-sulfonic acid

If 22.3 g (0.1 mol) of 2-amino-naphthalene-S-sulfonic acid, as described in .. 'Example 1, reacted, the' acid is obtained in a yield of 54 % .

Example 4 '. '.''' - '

a) The heterocyclic acid is obtained when starting from 31.7 g (0.1 mol) of 2-aminonaphtha-lin-1,7-disulfonic acid and this is as described in Example 1, implemented. It will be in a yield ... of

: '. ; 77 % received. ~ '·'' ^: . ^: · ' ^:

b) If 22.3 g (0.1 mol) of 2-amino-naphthalene-7-sulfonic acid, as described in Example 1, reacted, the desired sulfonic acid is obtained in a yield of 78 '% . _: ·

Example 5 ""

2-amino-naphtho [Z, 1-d] thiazole-r6,8-disulfonic acid ';

a) If 3I, '7 g (Ό, 1 mol) of 2-amino-naphthalene-5,7-disulfonic acid is assumed, then the desired acid, as described in Example 1, in

: obtained in a yield of 62 % .

b) starting from 38.3 g (0.1 mol) of 2-amino-naphthalene / trisulfonic acid '; (-1, 5,7) will be like. in Example 1 _: described, the thiazolesulfonic obtained in a yield of 68 % .

Example 6 .

2-amino-naphtho [2,1-d] thiazole-7,9-disulfonic acid

When 31.7 g (0.1 mol) of 2-amino-naphthalene-6,8-disulfonic acid (amino-G-acid) are reacted as described in Example T, the thiazole disulfonic acid is precipitated in a yield of 43%. on. ' -

") Example 7 .

2-amino-naphtho [2,1-d] thiazol-6-hydrozy-8-sulfonic acid

Starting from 23.9 g (0.1 mol) of 2-amino-naphthalene-5-OH-7-sulfonic acid (I-acid) - is, as described in Example 1, the corresponding hydroxysulfonic in a Aus. prey of 84 % .

Example 8 ... -.

2-amino-naphtho [2,1-d] thiazole-4,7-disulfonic acid

Are 31 »7 g (0.1 mol) of 2-amino-naphthalene-3,6-disulfo'n -.,. /. '. , acid (amino R acid), as described in Example 1,

, reacted, the corresponding disulxonic acid is obtained in a yield of 54%.

':. Example 9

2-amino-naphtho [2,1-d] thiazole-5,9-disulfonic acid

31.7 g (0.1 mol) of 2-amino-naphthalene-4,8-disulfonic acid are reacted as described in Example 1. The xhiazole-disulfonic acid is obtained in a yield of 51 % . , ^v .

- β - '; ,

Example TO ·. , ·.

2-naphtho-2,1-d-thiazole-9-OH-7-sulfonic acid

Starting from 23.9 g (0.1 mol); 2-A2nino-naphthalene-8-OH-6-sulfonic acid (1 "- acid), the hydroxy-naphthothiazole-sialfonic acid is obtained in a yield of 60 % .

Claims (2)

invention claims 1. A process for the preparation of α-amino-naphtho [2,1-d] thiazole mono / di- / OH-sulfonic acids of the formula Γ R =
R ² =
R ³ '= H, SO ₃ H H, SO-H, OH H, SO ₃ characterized in that .beta.-amino-naphthalene-mono / di- / tri-sulphonic acids or .beta.-aminaphthalene-hydroxysulphonic acids of the formula II R ¹ = H, SO H p. J> R ¹ - _ TT on π = Wj Dv ^ j ^ R ³ = .H |. SO ₃ H OH where R ¹ , R ^ or R "must always be a" SO ^ H group with rhodan salts in the presence of rhodanation. favoring substances in the presence of an oxidizing agent to ß-amino-naphtho [2,1-d ^ thiasol mono- / disulfonic acids dst, * -hydroxysulfonsäuren the formula 1. to be implemented * 2 «method according to item 1, characterized in that these reactions are carried out in aqueous-alcoholic medium. ,