SU1395636A1 - Method of producing 2,3-diphenylthiophenes - Google Patents

Abstract

The invention relates to organic sulfur substances, in particular the preparation of 2,3-diphenylthiophene (1) or its 4-methyl-substituted (II), used in the synthesis of biologically active substances. The process is carried out by the reaction of 1,2-diphenylbutanol-2 or its 3-methyl-substituted sulfur with 250-260 ° C. This improves the yield of the target compound.

Description

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This invention relates to a new process for the preparation of 2,3-diphenylthiophenes of formula (I)

CfiHs-- R

CeHg

V

where R is hydrogen or methyl, which can be used in the synthesis of biologically active substances. The purpose of the invention is to increase the yield and expansion of the range of target products, which is achieved by the interaction of diphenylbutanol of the formula (II)

SbH5-s (onsn-k

SbH5-CH2 CH3

where R - has the indicated values, with sulfur at 250-260 C.

The invention is illustrated by examples.

Example 1. Synthesis of 2,3-diphenylthiophene a.

113 g (0.5 mol) of 1,2-difenshenbutanol-2 and 48 g (1.5 mol) of sulfur in the form of pieces are placed in a round-bottom flask of heat-resistant glass, the flask is closed with a Dean-Stark trap with a water reflux condenser and heated a metal bath at 250-260 ° C for 2 hours. The water separated at the initial stage of the reaction is collected in a Dean-Stark trap and stepwise from the reaction sphere.

The release of thiophene is carried out by known methods. After recrystallization from alcohol, 56 g (47%) of 2,3-diphenylthiophene are obtained in the form of colorless crystals with m.p. 82-83 S.

Example 2. Synthesis of 4-methyl--2,3-diphenylthiophene,

The synthesis is carried out analogously to example 1 of 120 g (0.5 mol) of 1,2-diphenyl-3-methylbutanol-2 and 48 g (0.5 mol) of sulfur. After recrystallization from alcohol, 57.6 g (46%) of 4-methyl--2,3-diphenylthiophene are obtained in the form of colorless crystals with m.p. bb-bv C (not described in the literature).

Found,%: C 81.7; H 5.5; S 12,8

C H 1 S.

Calculated,%: C 81.55; H 5.64; S 12.81. PMR spectrum, ppm: 6.93

15

20

25

thirty

35

40 45

50 55

Tkof

);

95636 2

(Yun, m, ns, rum.); 6.71 (1H, s, H 1.97 (ZN, s,.

The resulting substances are f-colorless crystals, easily soluble in aromatic hydrocarbons, chloroform, carbon tetrachloride, dimethylformamide. Slightly soluble in alcohol, hexane, 10 petroleum ether. Practically insoluble in water, dilute acids and alkalis.

Example 3

When the ratio of reagents, as in example 1, the mixture is heated at 12 hours. After the usual treatment, 2,3-diphenylthiophene is obtained with a yield of 37%.

Example 4. When the ratio of reagents, as in example 2, the mixture is heated at 220 ° C for 9 hours. After the usual treatment, 4-methyl-2,3-diphenylthiophene is obtained in 40% yield.

Example 5. When the ratio of reagents, as in example 2, the mixture is heated for 4 hours. After the usual treatment, 4-methyl-2,3-diphenylthiophene is obtained with a yield of 42%.

Similarly, 2,3-diphenylthiophene is obtained with a yield of 43%.

Thus, the proposed method allows to increase the yield of the known 2,3-diphenylthiophene to 47% versus 32% and to obtain a new compound 4-methyl-2,3-diphenylthiophene, thereby expanding the range of diphenylthiophenes,

Claims (1)

Invention Formula Method for producing 2,3-diphenylthiophenes of formula (I) SbH5-.k s where R is hydrogen or methyl, which is characterized by the fact that, in order to increase the yield and expansion of the target product range, diphenylbutanol of the formula (II) SbH5-S (OH) -CH-K SbH5-CH2 CH3 where R has the indicated values, is reacted with sulfur at 250-260 C. SbH5