Patent GB-1156483-A (GB)
Title: Pyridine Flavouring Agents
Inventor: WINTER M
IPC: A23L27/20
Filed: 1966-05-02
Abstract: 1,156,483. Pyridine derivatives. R. FIRMENICH, G. FIRMENICH, R. E. FIRMENICH, and F. H. FIRMENICH, [trading as FIRMENICH & CIE.]. 2 May, 1966 [30 April, 1965; 18 April; 1966], No. 2384/69. Divided out of 1,156,472. Heading C2C. [Also in Division A2] 2-Butoxy-pyridine was prepared according to the method described in J.A.C.S. 69, 1803 (1947) by condensing 0À17 mole of 2-bromopyridine with 0À195 mole of sodium butoxide. By distillation of the reaction product there were obtained 15 g. of 2-butoxy-pyridine distilling at 78‹ C./10 mm. Hg. n D <SP>23</SP> = 1À4880; d 4 <SP>23,4</SP> = 0À9723. 4-(γ-Pyridyl)-butan-2-one was prepared as follows: 8 ml. of 2-n NaOH solution were added to a mixture of 10À8 g. (0À1 mole) of pyridine-4- aldehyde, 100 ml. of water and 10 ml. of acetone at 12-15‹ C. After a reaction time of 3 minutes the reaction mixture was neutralized with 10% aqueous acetic acid, saturated with NaCl and extracted with ether. After removal of the ether the residue was distilled. There were obtained 8À4 g. of 4-(γ-pyridyl)-3-buten-2- one as a yellow oil of b.p. 135-138‹ C./0À07 Torr. 5À24 g. of this product were dissolved in 30 ml. of ethanol and hydrogenated in the presence of 4 g. of Ni-catalyst. Distillation of the reaction product yielded 4-(γ-pyridyl)- butan-2-one of b.p. 83-85‹ C./0À05 Torr; n 4 <SP>27</SP> = 1À047; n D <SP>27</SP> = 1À516. (2-(pyridyl-2)-ethyl methyl sulphide) was prepared as follows: 2-Vinylpyridine was reacted with methylmercaptan by the action of UV light in the presence of trace amounts of benzoyl peroxide and diphenyl sulphide. The product has a b.p. of 48‹ C./0À03 mm. Hg. The same method was used for preparing 2-(pyridyl-2)-ethanethiol acetate, except that thioacetic acid was used instead of methylmercaptan. The product has a b.p. of 80‹ C./ 0À02 mm. Hg. 2-Methylthio-pyridine was prepared according to the method described in Houben-Weyl, 4th ed., vol. 9, 7 (1955) by alkylating 2-mercaptopyridine with methyl halide. The resulting pyridinium salt was neutralized with NaOH and the base thus obtained extracted and distilled. The product had a b.p. of 67-68‹ C./ 10 mm. Hg. 2-Ethylthio-pyridine was prepared by the same method as used for compound (V) c., except that ethyl halide was used instead of methyl halide. The product had a b.p. of 77- 77À5‹ C./8 mm. Hg. (Pyridyl-2)-thiol acetate was prepared by reacting acetic anhydride with 2-mercaptopyridine in alkaline medium according to the method described in Houben-Weyl, 4th ed., vol. 9, 753 (1955) and in J.A.C.S. 59, 1089 (1937). The product has a b.p. of 117-118‹ C./ 9 mm. Hg. 2-(Pyridyl-2)-ethyl sulphide was prepared by the same method as used for compound (V) h., except that ethyl-mercaptan was used instead of methylmercaptan. The product has a b.p. of 62‹ C./0À005 mm. Hg. (Pyridyl-2)-methyl ethyl sulphide was prepared by the same method as used for compound (V) 1. The product has a b.p. of 107- 110‹ C./10 mm. Hg. (Pyridyl-2)-methanethiol acetate was prepared by reacting acetyl chloride with 2-mercaptomethylpyridine in alkaline medium. The product has a b.p. of 102-103‹ C./9 mm. Hg.