Wednesday, 16 May 2012

Laboratory Synthesis Of Famotidine

Famotidine Synthesis

Use: ulcer therapeutic, H2-receptor antagonist

The reaction ot S-(2-aminothiazol-4-ylmethyl)isothiourea (I) with 3-chloropropionitrile (II) by means of NaOH in ethanol - water gives 3-(2-aminothiazol-4-ylmethylthio)propionitrile (III), which is condensed with benzoyl isothiocyanate (IV) in refluxing acetone to afford 3-[2-(3-benzoylthioureido)thiazol-4-ylmethylthio]propionitrile (V). The hydrolysis of (V) with K2CO3 in acetone - methanol - water yields 3-(2-thioureidothiazonl-4-ylmethylthio)propionitrile (VI), which by methylation with methyl iodide in refluxing ethanol is converted into 3-[2-(S-methylisothioureido)thiazol-4-ylmethylthio]propionitrile hydroiodide (VII). The reaction of (VII) with NH3 and NH4Cl in methanol at 90 C in a pressure vessel affords 3-(2-guanidinothiazol-4-ylmethylthio)propionitrile (VIII), which by partial alcoholysis with methanol by means of dry HCl in CHCl3 is converted into methyl 3-(2-guanidinothiazol-4-ylmethylthio)propionimidate (IX). Finally, this compound is treated with sulfamide in refluxing methanol.
Drugs Fut 1983, 8, 1, 14
US 4283408
DOS 2 951 675 (Yamanouchi; appl. 21.12.1979; J-prior. 2.8.1979).
DOS 3 008 056 (Yamanouchi; appl. 3.3.1980; J-prior. 6.3.1979, 23.6.1979).
GB 2 052 478 (Yamanouchi; appl. 6.3.1980; J-prior. 6.3.1979, 23.6.1979).
GB 2 055 800 (Yamanouchi; appl. 20.12.1979; J-prior. 2.8.1979).
synthesis of S-[2-aminothiazol-4-ylmethyl]isothiourea:
Spragne, J.M.; Lund, A.H.; Ziegler, C.: J. Am. Chem. Soc. (JACSAT) 68, 2155 (1946).


  1. Famotidine drug used to treat certain conditions caused by too much acid being produced in your stomach, such as stomach ulcers, ulcers of the upper part of the intestine, acid reflux or heartburn, and indigestion. acid is generally produced to digest food. exceedind acid may causes problem.

  2. Famotidine used to treat and prevent ulcers in the stomach and intestines. You must take this pill 30 mins before you taking food.

  3. Famotidine is used to treat and prevent ulcers in the stomach and also this resolves gastroesophageal reflux diseases.It has a balancing eefect on bodily functions.