Heterocyclic Compounds Flashcards
1
Q
A
2H-Pyran
- Neutral
2
Q
A
Pyrillium
- fixed cation
3
Q
A
Furan
- Neutral
4
Q
A
Thiophene
- Neutral
5
Q
A
Oxazole
- very weak base
- pka= 0.8
6
Q
A
Thiazole
- very weak base
- pka= 2.5
7
Q
A
Isoxazole
- pka = low
- neutral
8
Q
A
Isothiazole
- pka = low
- neutral
9
Q
A
Pyrrole
- pka= high
- neutral
10
Q
A
Indole
- pka= high
- neutral
11
Q
A
Pyrazole
- very weak base
- pka= 2.5
12
Q
A
Imidazole
- Base
- pka= 7.1
13
Q
A
Benzimidazole
- Base (& very weak acid)
- 12.3, 5.7
14
Q
A
Tetrazole
- weak acid
- pka = 4.8
- bioisostere for carboxylic acid
15
Q
A
Pyridine
- Weak base
- pka= 5.2
16
Q
A
Pyridazine
- very weak base
- pka= 2.1
17
Q
A
Pyrimidine
- very weak base
- pka= 1.1
18
Q
A
Pyrazine
- very weak base
- pka= 0.6
19
Q
A
1,3,5 -Triazine
- Neutral
- pka= Low
20
Q
A
Quinoline
- weak base
- pka= 4.8
21
Q
A
Isoquinoline
- weak base
- pka= 5.1
22
Q
A
Coumarin
- Neutral
23
Q
A
Isocoumarin
- Neutral
24
Q
A
Flavone
- Neutral
25
Isoflavone
* Neutral
26
Purine
* very weak base & **very weak acid**
* pka= 8.9, **2.5**
27
Adenine
* Weak base & **very weak acid**
* pka= 9.8, **3.8**
28
Guanine
* Very weak base & **very weak acid**
* pka= 9.4, **2.4**
29
Xanthine
* very weak base & **weak acid**
* pka= 7.7, **0.8**
30
Cytosine
* Weak base
* pka= 4.5
31
Uracil
* very weak acid
* pka= 9.5
32
Thymine
* very weak acid
* pka= 9.5
