Aryl Halides to Thiophenols using Thiourea

Japanese Patent 63-203632

Translation by 6079_Smith_W_II
HTML by Rhodium

...I've been having a bit of trouble with this one -- the scan quality of the document is not very good in either of the versions I have, there are some complicated (to me) run-on sentences, whine whine excuses etc etc... mainly the problem is I still suck at Japanese.

Here's the meat of the patent, the experimental part...

Patent: JP63203632 (1988-08-23)
Inventors: TSUJII YASUHIRO; UENISHI HISAYOSHI, KIMURA TOKIYA
Applicant: ISHIHARA SANGYO KAISHA LTD
Application: JP19870035316 (1987-02-18)
IPC: C 07 B 45/06; C 07 D 213/70

(Skipping summary description, theory stuff for now ...)

Example of Execution 1

181.5g 2-chloro-3-trifluoromethylpyridine and 114g thiourea were dissolved in 91g acetic acid, and reacted at 90°C for 1 hour. After the end of this reaction, and after the reaction mixture cooled, 600ml of 20% sodium hydroxide solution was thrown in; next the aqueous layer was washed with methylene chloride and afterwards the pH of the solution was adjusted to 6-7 with hydrochloric acid; the formed crystals were separated, washed, and dried, to obtain 166g 2-mercapto-3-triflouromethylpyridine (yield 92.7%). Furthermore, in this reaction process bad odors were not generated.

Comparison example

A reaction was performed in a similar manner to Example of Execution 1 above with the exeptions that the 91g of acetic acid was replaced with 1L of ethanol, the reaction temperature was 80 instead of 90°C, and the reaction time was 26 hours instead of 1 hour. 98.9g of the target compound was obtained (yield 55%) upon completion of this halide compound and thiourea reaction. Also, in this reaction process a bad odor was generated.

Examples of Execution 2-15

These were performed in the manner of Example of Execution 1, with the raw materials used shown in the following Table 1-1, and the reaction conditions shown in Table 1-2; results are shown in Table 1-2.

Table 1-1
Ex.
No.
Raw materials
Halide substance
Specific Carboxylic Acid
thiourea
Type
Quantity
Type
Quantity(g)
2
2-chloro-5-trifluoromethylpyridine
200 g
acetic acid
100 g
167 g
3
2-chloro-3-trifluoromethylpyridine
363 g
50% aqueous
acetic acid
360 g
228 g
4
2-fluoro-3-trifluoromethylpyridine
16.5 g
acetic acid
16 g
15.2 g
5
2-bromo-3-methylpyridine
17.2 g
acetic acid
8 g
15.2 g
6
2-chloro-5-hydroxycarbonylpyridine
10 g
acetic acid
10 g
7.8 g
7
2-chloro-5-aminocarbonylpyridine
5.0 g
acetic acid
10 g
4.9 g
8
2-chloro-5-cyanopyridine
4.0 g
acetic acid
4 g
4.4 g
9
2-chloro-5-nitropyridine
10.0 g
acetic acid
5 g
9.6 g
10
2,3,5-trichloropyridine
36.5 g
acetic acid
18 g
22.8 g
11
2-bromopyridine
10.0 g
acetic acid
5 g
9.6 g
12
5-bromo-2-chloropyridine
10.0 g
acetic acid
10 g
7.7 g
13
5-bromo-3-methylene thiazole
3.0 g
acetic acid
10 g
2.6 g
14
benzylbromide
4.5 g
acetic acid
5 g
4.4 g
15
2-bromothiazole
6.0 g
acetic acid
6 g
5.6 g
Table 1-2
Ex.
No.
Reaction Condition of Alkaline Substance
Goal Substance
Temp
Time
Alkali
Type
Alkali
Quantity
Species
Yield
2
70-80°C
1.3 h
NaOH
174g
2-mercapto-5-trifluoromethylpyridine
88.3%
3
95-100°C
1 h
NaOH
310g
2-mercapto-3-trifluoromethylpyridine
94.3%
4
110°C
6 h
NaOH
14g
2-mercapto-3-trifluoromethylpyridine
59%
5
95°C
1 h
NaOH
15g
2-mercapto-3-methylpyridine
53.6%
6
95°C
1 h
NaOH
20g
2-mercapto-5-hydroxycarbonylpyridine
83.3%
7
95°C
0.3 h
NaOH
10g
2-mercapto-5-aminocarbonylpyridine
91.6%
8
85°C
2 h
NaOH
5g
2-mercapto-5-cyanopyridine
94.1%
9
90°C
0.5 h
NaOH
10g
2-mercapto-5-nitropyridine
90%
10
100°C
2 h
NaOH
30g
2-mercapto-3,5-dichloropyridine
73.3%
11
70°C
2 h
NaOH
9.5g
2-mercapto-pyridine
95%
12
80°C
0.3 h
NaOH
8g
5-bromo-2-mercaptopyridine
98%
13
75°C
2 h
NaOH
8g
3-methyl-5-mercaptoisothiazole
96%
14
80°C
1 h
NaOH
3g
benzylthio alcohol
92%
15
80°C
0.5 h
NaOH
7g
2-mercaptothiazole
95%

Similarly with the exception of the halide substance, from for example 2-bromopyrazine, 3-bromopyridazine, 4-bromo-1-methylimidazole, 2-bromo oxazole, 5-bromo-4-nitro-isoxazole, 5-bromo-1-methyl-4-nitropyrazole, 3-bromo-1,2,4-triazole, and 2-bromotriazine, used in the reaction of Examples of Execution 1-15 above, 2-mercaptopyrazine, 3-mercaptopyridazine, 4-mercapto-1-methyl-imidazole, 2-mercapto oxazole, 5-mercapto-4-nitroisoxazole, 5-mercapto-1-methyl-4-nitropyrazole, 3-mercapto-1,2,4-triazole, and 2-mercaptotriazine would be obtained.

{Invention conclusion....)


References

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