VISUDHA YUDA SLEHA YUDE PRARTHANA

This strong prayer is in malayalam. Say this prayer nine times a day for nine days . you will fulfill your prayer .
Invite as many in here & spread the word.
- Believer

 

Laboratory Synthesis Of Ciprofloxacin

 Ciprofloxacin Synthesis

Ciprofloxacin

Use: antibacterial

LD50: 122 mg/kg (M, i.v.); 5 g/kg (M, p.o.);
 207 mg/kg (R, i.v.); >2 g/kg (R, p.o.)

 The condensation of 2,4-dichloro-5-fluorobenzoyl chloride (I) with diethyl malonate by means of magnesium ethoxide in ether gives diethyl 2,4-dichloro-5-fluorobenzoylmalonate (II), which is partially hydrolyzed and decarboxylated with p-toluenesulfonic acid water yielding ethyl 2,4-dichloro-5-fluorobenzoylacetate . Condensation of this with triethyl orthoformate  in refluxing acetic anhydride affords ethyl 2-(2,4-dichloro-5-fluorobenzoyl)-3-ethoxyacrylate (III), which is treated with cyclopropylamine (IV) in ethanol to give ethyl 2-(2,4-dichloro-5-fluorobenzoyl)-3-cyclopropylaminoacrylate . The cyclization of ethyl 2-(2,4-dichloro-5-fluorobenzoyl)-3-cyclopropylaminoacrylate with NaH in refluxing dioxane yields 7-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (V), which is finally condensed with piperazine  in hot DMSO to afford the target compound ciprofloxacin.

Synthesis references

1. Reddy, P.G.; Baskaran, S.; Microwave assisted amination of quinolone carboxylic acids: An expeditious synthesis of fluoroquinolone antibacterials. Tetrahedron Lett 2001, 42, 38, 6775
2. Drugs Fut1984,9,(3):179
3. EP 0078362
4.  JP 4253963
5. JP 58074667
6. US 4620007
7. US 4670444
8. EP 657448 

<script type="text/javascript">
ch_client = "sanalpcp";
ch_width = 500;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>

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.

 

SYNTHESIS REFERENCE

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).