206 Index
Proton pump inhibitor 170
Protoporphyrin IX 179
Protozoa 175
Psoralen 179
Psoralen-UltraViolet A 179
Psoriasis 179
Pteridine 159
7 H-purine, see Purines
9 H-purine, see Purines
Purines
acidity 124
a 6-alkylamino-, from Dimroth rearrangement 129
N-alkylation, regiochemistry 125
2-amino-, ring synthesis 130
a 2-amino-, diazotisation 129, 130
2-amino-6-(1,2,4-triazol-4-yl)-, N-9–alkylation 127
6-amino-, diazotisation 129
a 6-amino-, from Dimroth rearrangement 124
a 6-amino-, side-chain N-alkylation 129
a 2-amino-6-chloro-, reaction with Me 3 N/cyanide 127
6-amino-7-methyl-, ring synthesis 131
N-9–arylation, copper-catalysed 126
basicity 124
C-8–bromination 125
2-chloro-, reaction with hydrazine 127
6-chloro-, reaction with hydrazine 127
6-chloro-9-phenyl-, reaction with cyanide 127
with p-toluenesulfi nate 127
2,6-diamino-, conversion into 6-(1,2,4-triazol-4-yl)- 127
2,6-diamino-8-(4-methoxyphenyl)-, ring synthesis 130
a 2,6-dione-, synthesis via a 2-amino-diazotisation 130
disconnections for ring synthesis 130
electrophilic substitution 125
2-fl uoro-, synthesis via 2-amino-diazotisation 130
halo-, nucleophilic displacement, regioselectivity 127
a 2-iodo-, Sonogashira reaction 128
a 2-iodo-, synthesis via 2-amino-diazotisation 130
a 6-lithio-, from the iodo- 128
an 8-lithio-, from the 6-lithio- 128
from the purine 128
C-2–nitration 125
nucleophilic substitution, leaving groups 127
numbering 3, 122
a 6-one-2-thione-, ring synthesis 131
6-one-2-bromo-, reaction with aniline 127
6-one, 2-trifl uoromethyl-9-(4-methylphenylmethyl)-, ring
synthesis 131
6-one-9-methyl-, N-1–alkylation 129
6-one, reaction with P 4 S 10 129
ribosides, N-alkylation 126
N-9–ribosylation 126
tautomerism 122
6-thione, synthesis from 6-one 129
6-p-toluenesulfonyl-9-phenyl-, reaction with cyanide 127
a 6-(1,2,4-triazol-4-yl)-, hydrolysis to 6-one 127
2,6,8-trichloro-, from uric acid 123, 129
Purinethol 178
PUVA, see Psoralen-UltraViolet A
Pyralone 191
2 H-Pyrans 3
from pyryliums by reduction 71, 72
ring opening 72
4 H-Pyrans from pyryliums by reduction 72
Pyran, 3,4-dihydro-2H-, use to protect alcohols 154
tetrahydro- 154
2-Pyranone, a 4-tri-n-butylstannyl-, from Diels–Alder
reaction 141
a 5-tri-n-butylstannyl-, from Diels–Alder reaction 141
Pyran-3(6H)-ones, 6-hydroxy-, from 2-(1-hydroxyalkyl)furans
103
2-Pyrazinone, 6-methyl-, ring synthesis 59
Pyrazines
2-amination (Chichibabin) 14, 50
2-amino-, basicity 57
conversion into 2-pyrazinone 58
diazotisation 58
3-amino-2-carboxylic acid, ring synthesis 59, 60
basicity 10, 48
biosynthesis 187
3,6-dibromo-2-methoxy-, in Suzuki–Miyaura reaction 91
2,3-dicarboxylic acid, from quinoxaline 60
2,3-dicyano-5,6-diphenyl-, ring synthesis 60
2-chloro-, in Suzuki–Miyaura reaction 54
2-chloro-3-ZnCl, in Negishi reaction 54
2-ethyl-3-methyl-, ring synthesis 59
2-iodo-, formation of Grignard 53
2-lithio-3-fl uoro-, from 3-fl uoro- 52
2-lithio-, from pyrazine 52
2-methoxy-, reaction with malononitrile anion 51
2-methyl-, chlorination 49
numbering 2
N-oxide, 2-amino-, reaction with Me 3 SiCN 57
N-oxide, 2,5-dimethyl-, reaction with POCl 3 57
perfumes and fl avours 186, 191
reaction with EtOCO radical 52
Pyrazinium-3-olate, 1,5-dimethyl-, dipolar cycloaddition 55
2-Pyrazinone, 3,5-dichloro-1-methyl-, Diels–Alder 55
3-phenyl-, nitration 50
Pyrazino[2,3-d]pyrimidine 60
3-Pyrazolone
condensation with araldehyde 115
1-phenyl-, 4-bromination 110
tautomerism 115
5-Pyrazolone
2,3-dimethyl-1-phenyl-, Vilsmeier reaction 115
3-methyl-1-phenyl-, ring synthesis 119
Pyrazoles
3-acetamido-, 4-nitration 110
acidity 10, 110
1-amino, reaction with NiO 2 142
3-amino-, 4-bromination 110
5-amino-3-cyano-1-(2,6-dichloro-4-trifl uoromethylphenyl)-,
ring synthesis 183
5-amino-3-cyano-1-(2,6-dichloro-4-trifl uoromethylphenyl)-,
reaction with CF 3 SOCl 183
N-arylation 111
basicity 10, 107
bromination 110
Chan–Lam reaction 30, 111
copper-catalysed N-substitution with a boronic acid 30
3-(dimethoxymethyl)-, ring synthesis 120
3,5-dimethyl-, ring synthesis 119
disconnections for ring synthesis 119
electrophilic addition 107