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The Hive => Chemistry Discourse => Topic started by: Elementary on May 06, 2002, 02:33:00 AM

Title: German patent translation
Post by: Elementary on May 06, 2002, 02:33:00 AM

Would someone be kind enough to translate a two page Germany patent to English for me, or at least tell me if the process is described elsewhere.

Patent DE832755 (http://l2.espacenet.com/dips/viewer?PN=DE832755&CY=gb&LG=en&DB=EPD)

Many Thanks

Elementary

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Don't cry for me I'm the cleaner

Title: The essential stuff...
Post by: bocuse on May 06, 2002, 06:45:00 AM

DE832755
Process for the preparation of thienylacetic acid and derivatives.

They do a Willgerodt from 2-acetothienone to get an amide or substituted amide, then they prepare 2-thienylacetic acid from it. Normally, Willgerodt yields are low because 2-acetothienon is sensitive to ammonium sulfide, sulfur, ammonia and other nitrogen bases. They get better yields by lowering reaction temperatures and they use higher concentrations of ammonia, ammonium polysulfide and sulfur to assure a better conversion. Water miscible organic solvents used are dioxan, pyridine, thf. The process is said to be suitable to prepare amides of other thienylacetic acids in good yields.

Example:
30g 2-acetothienone, 66ml conc. ammonia solution, 45g sulfur, 36g yellow solution of ammonia polysulfide and 54ml dioxan are heated in a closed vessel during 1 hour to 142°C, it is kept at this temp for 3.5 hours and then heated to 152°C for 15 min. Usual workup of the reaction mixture yields 23g = 68% of theory 2-thienylacetic acid amide, bp 146.5°. Following the usual procedure for 'Verseifung' [=soapification? 'Verseifung' in geman means ester breakup using alkalis, like soap (seife) is made] 2-thienylacetic acid, bp 64°C is prepared.

The rest is the usual patent blah blah, claims and that. Sorry i don't have that much time by now. I know my english isn't that good, so ask if you're not sure how i meant something.

Hope this helps...paul

Title: 'Verseifung' = Saponification in english.
Post by: Rhodium on May 06, 2002, 03:08:00 PM

'Verseifung' = Saponification in english.

Title: Saponification
Post by: bocuse on May 06, 2002, 06:36:00 PM

Whew!

I'm learning alot of english here!

Actually, i'm know the hive for about four years or so.. but reading and writing are two different stories.

The old Willgerodt pipe bomb topic.. a two inch pipe with caps, an electric fryer, a sandbag bunker and 100 meter extension cord  ;D  - i'm looking forward to seeing that work!

cheers.. paul

Title: Morpoline, not pressure
Post by: halfapint on May 06, 2002, 08:50:00 PM

The most effective way to approach the Willgerodt would seem to bee using the effort to come up with the reagent which won't require pressure, namely morpholine, instead of working for a special-use apparatus. One or two steps should give this substance,

Post 304828 (missing)

(SideArm: "Morpholine making", Chemistry Discourse). On the other hand, building gadgets is fun, according to your personal preference. Yet if you want to degrade polystyrene to achieve styrene monomer, you already have one construction job cut out for you, for the pyrolysis uses a very high temperature distillation. I'd suggest building the styrene still, but making the morpholine to save the extra effort of making a (lower-yielding) bomb reaction vessel.

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