Automated synthesis: Development of a new apparatus friendly to synthetic chemists (MEDLEY)

Organic Process Research and Development

Volumn 4, Issue 5, 2000, Pages 333-336

  Orita, Akihiro ^a   Yasui, Yutaka ^a   Otera, Junzo ^a  

^a OKAYAMA UNIVERSITY OF SCIENCE   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0034345189     PISSN: 10836160     EISSN: None     Source Type: Journal    
DOI: 10.1021/op000046c     Document Type: Article

References (11)

1. For recent reviews: (a) Lindsey, J. S. Chemom. Intell. Lab. Syst. 1992, 17, 15.
2. (b) Sugawara, T.; Cork, D. G. Lab. Rob. Autom. 1996, 8, 221.
3. (c) Harre, M., Tilstam, U.; Weinmann, H.; Org. Process Res. Dev. 1999, 3, 304.
4. ARS (Automatic Reaction System) is an automatic reaction controller commercially available from Sogo Pharmaceutical Co., Ltd., Tokyo. ARS is equipped with sensors for monitoring the temperatures of reaction mixture and methanol coolant. It also determines electric currents for driving the pumps to load reagents as well as the pump to circulate the cold methanol, according to the programmed reaction temperature. The feedback circuit is running constantly on ARS so that the rate of reagent loading could be maximized by balancing the pump powers for both reagent loading and methanol circulation.
5. The sequencer is originally designed and constructed by Sogo Pharmaceutical Co., Ltd., Tokyo for multistep reactions. In the sequencer, the drivers of pumps and memories for input of the order and the amount of reagents are incorporated.
6. The volumetric pumps and drivers are commercially available from Yamazen Corporation, Tokyo.
7. The reaction temperature is highly influenced by the ambient temperature and humidity. Thus, repetition of identical reactions directed by even the same reaction program resulted in varied reaction periods when each task was programmed in terms of the time. In these operations, therefore, we need to set long performance times to fully secure the completeness of the tasks. Thus, we constructed a time-independent control function which can initiate the next task immediately after completion of the preceding one. This control system is also highly useful to overcome "overnight stirring problem" which causes troubles on occasion in the process development. As pointed out in an article by Stinson, S. C. in Chem. Eng. News 1999 77, 35, synthetic chemists frequently leave reactions to run overnight simply because of their convenience; yet it may happen that this is too long and gives rise to a worse outcome than it might be actually.
8. -1 under maximum power.
9. (a)Hayashi, N.; Sugawara, T.; Shintani, M.; Kato, S. J. Auto. Chem. 1989, 11, 212,
10. (b) Hayashi, N.; Sugawara, T.; Kato, S.; J. Auto. Chem. 1991, 13, 187.
11. (c) Sugawara, T.; Kato, S.; Okamoto, S. J. Auto. Chem. 1994, 16, 33.