SYSTEMIC APPROACH TO TEACHING AND LEARNING HETEROCYCLIC CHEMISTRY (SATLHC) 2008 A. F. M. Fahmy, M. A. El-Hashash Faculty of Science, Department of Chemistry and Science Education Center, Ain Shams University, Abbassia, Cairo, EGYPT W.A.Abduo National research Center,Cairo,Egypt

The linear representation (1a) Vis systemic representation (1b) of concepts. Fig: 1a concept Fig: 1b concept

 Systemic Teaching Strategy: we started teaching of any unit by Systemic diagram (SD0) that has determined the starting point of the unit, and we ended with a final systemic diagram (SDf) and between both we crossover several Systemics(SD1,SD2,...) SD0 SDf SD2 SD1 Fig (2): Systemic teaching strategy

SATLHC Pure Applied - Synthesis - E-Substitution - Nu-Substitution - Addition - Cycloaddaition - Ring Opening - Het. Int. Conversion - Pharmaceuticals - Food Additives - Plant growth regulators - Insecticides - Herbicides - Corrosion Inhibitors - Super conductors. - Dyes - Photographic materials etc..) [LATLHC] Z Het. X Z Y Z E Z F X,Y,E,F [SATLHC] Z = N, O, S (Functional Groups) Z Het.

 Application of SATL In Heterocyclic Chemistry:  A course on heterocyclic chemistry using the SATL technique was organized and taught to 3rd year students at Ain Shams University. A portion of the one-semester course (10 lectures, 20 hours) was taught to students during the academic years.  1999/2000, 2000 / 2001, and 2003 / 2004

 Linear VS Systemic Study in Heterocyclic Chemistry:  Linear study in heterocyclic chemistry means servay study on the reactivity of the heterocycles to give products in a separate chemical reactions (Alkylation, acylation, Nitration, Sulphonation, formylation, …..).  Systemic study in heterocyclic chemistry means servay study on the reactivity of both heterocycles and substituents and their all possible chemical relations.

Heteroatom: [(Z) = NH, O, S] Substituents:[(G) = R, - CH 2 - X, - -CH 2 - OH - NH 2, - CHO, - COR, - COOH] G Reactivity of the Nucleus Reactivity of the Substituents Z

Figure 3: summarizes comparative reactivites of the five membered heterocycles as model heterocyclic compounds, and their possible relations.

 The diagram (4) represents the reactivity of heterocyclic nucleus, and gives the linear separated chemical relations between (pyrrole, furan, thiophene), and their compounds.  We use heterocyclic chemistry to illustrate, again, how a subject can be organized systemically. SD1 summarizes the comparative reactivities of both heterocyclic nucleus and substituents.

 In the systemic diagram (SD1) there are unknown chemical relations (1-7) between heterocyclic compounds. These relations will be clarified later during the study of pyrrole, furan and thiophene.

ASSESSMENT – I ON SD1 ASSESSMENT – I ON SD1 QI) Draw systemic diagrams illustrating the chemical relations between compounds in each of the following sets.

A I - 1

QII) Complete the following systemic diagrams: A II - 2

Reactions of pyrrole, and Pyrrole compounds(asExample) I-Pyrrole: (Prerequisites SD1)  We can summarize the reactions of pyrrole in the following diagram (Fig. 4).

 The diagram (Fig. 4) represents the reactivity of (pyrrole nucleus), and gives the linear separated chemical relations between pyrrole and its compounds.  We can illustrate the chemical relations in (Fig. 4) systemically by modification of SD1 to SD2 (Z = NH):

 Systemic diagram (SD2) shows know chemical relations between pyrrole and its compounds. We have the unknown chemical relations between pyrrole compounds (1-8), and should be clarified during the study of pyrrole compounds.

 After Study of pyrrole compounds [G = R, CH 2 OH, CHO, RCO, COOH, NH 2 ): We can modify (SD 2 to SD 3) by adding chemical relations (1 – 7).

ASSESSMENT – II ON SD3 ASSESSMENT – II ON SD3 QI) Draw systemic diagrams illustrating the chemical relations between compounds of each of the following sets: (clockwise) N H N N H COOHCHO,,1- H N H,,, NO 2 N H COOH N H CHO N H 2- H HH H N,,, NN N 2 Ph N COONH 4 COOH 3-

A I - 1 N H N H CHO N H COOH aq. alk. 200 o C heat KMnO 4 i)DMF, POCl 3 ii) aq. Na 2 CO 3

QII) Complete the following systemic diagrams: 1- N H COOH Ac 2 O- 10  C AcONO 2 / curtius rearrangement SOCl  c heat NaN N H N H N H DMF, POCl 3 aqNa 2 CO 3 aq.alk. KMnO 4 CHO COOH Then give the systemic chemical relations in a list

A II - 2 N H N H aq. alk. KMnO 4 bromination COOH N H N H CHO Br NBS, THF Vap. phase decarbonylation i) DMF, POCl 3 ii) Na 2 CO 3 heat, 200  c Above chemical relations in a list: N H N H N H COOH CHO N H N H N H Br COOH N H N H N H CHO N H N H N H COOH N H CHO Br

QIII) Arrange the following compounds in the right places in the following (SD.): CH 3 N H N,, H N H CHO N, H N H COOH NO 2 CH 3 MgX LTA/ AcOH  Oxid alk. KMnO

QIV) How can you make the following conversions: 1)Pyrrole to pyrrole -2-carboxylic acid. 2)2-Hydroxymethylpyrrole to 2-phenylazopyrrole. 3)Pyrrole -2-carboxylic acid to 2-bromopyrrole. 4)2-Methylpyrrole to pyridine. 5)2- Formyl pyrrole to 2-Nitropyrrole. 6)Pyrrole -2- Carboxylic acid to 2-aminopyrrole. A IV - 2 N H N H COOH PhN 2 N 2 Ph + N H N H CH 2 OH Diborane CH 3 Chromic acid A IV - 4

QV) Rearrange the compounds in the following SD to give correct chemical relations: N H COOH N H N H NBS/THF COONH 4 N H Br hydrolysis (NH 4 )2 CO 3 / 130  C Seald vessel Br  C heat AV) N H COOH N H N H NBS/THF COONH 4 N H Br hydrolysis (NH 4 )2 CO 3 / 130  C Seald vessel Br  C heat

QVI) Which of the following systemics are true and which are fals: A VI) a: (x); b: ( )c: (x); d: ( )

QVII) Put ( ) Infront of the correct systemics: A VI) a: (x); b: (x)c: ( ); d: (x) The systemic diagram represents the correct chemical relations between pyrrole and its compounds is one of the following:

1- Heterocyclic derivative to another Hetercyclic derivative: Example: Systemic Teaching Strategies For Uses Of Heterocycles In Synthesis

2- Aliphatic compound to another aliphatic compound via Heterocycle:

3- Heterocycles to homocycles:

 Conclusion:  After the experimentation of SATLHC in Egypt we reached to the following conclusions: 1) SATLHC improved the students ability to view (HC) from a more global perspective. 2) SATLHC helps the students to develop their own mental framework at higher-level cognitive processes (application, analysis, and synthesis). 3) SATLHC increases students ability to learn subject matter in a greater context. 4) SATLHC increases the ability of students to think globally.

 References: (1) Taagepera, M.; Noori, S.; J. Chem. Educ. 2000, 77, (2) Fahmy, A. F. M.; Lagowsik. J. J.; J. Chem. Educ. 2003, 80, (9), (3) Fahmy, A. F. M., El-Shahaat, M. F., and Saied, A., International Workshop on SATLC, Cairo, Egypt, April (2003). (4) Fahmy, A.F.M., Lagowski, J.J.; Systemic Approach in Teaching and Learning Aliphatic Chemistry; Modern Arab Establishment for printing, publishing; Cairo, Egypt (2000). (5) Fahmy A. F. M., El-Hashash M., Systemic Approach in Teaching and Learning Heterocyclic Chemistry. Science Education Center, Cairo, Egypt (1999). (6) Fahmy A. F. M., Hashem, A. I., and Kandil, N. G.; Systemic Approach in Teaching and Learning Aromatic Chemistry. Science, Education Center, Cairo, Egypt (2000). (7) Fahmy, A. F. M.; Hamza M. S. A; Medien, H. A. A.; Hanna, W. G., M. Abedel-Sabour; and Lagowski; J. J.; Chinese J. Chem. Edu., 23 (12) 2002, 12, 17th IEEC, Beijing August (2002).17th IEEC, Beijing August (2002).