Cloning, expression and N-terminal formylation
of ESAT-6 of Mycobacterium tuberculosis H37Rv.
Islam, "Pd nanoparticles decorated on hypercrosslinked microporous polymer: a highly efficient catalyst for the formylation
of amines through carbon dioxide fixation," Chem-CatChem, vol.
When R1 = H, DHPMs 4 could be alkylated at [N.sub.1]  whereas the formylation
or acylation of [N.sub.3] of 4 furnishes the [N.sub.3]-formylated or [N.sub.3] acylated derivatives .
However, there are several reasons why lysine formylation
might have significant biological consequences.
Compounds 4 and 5a were synthesized based on modified literature methods (Scheme 1) [30-33], key intermediate 13 obtained from compound 7 via Vilsmeier-promoted halogenation and formylation
, one-pot cascade condensation with 2-furoic acid hydrazine (9) and 2-hydroxyethyl hydrazine (11), Dimroth rearrangement to effect triazole formation, and finally bromination with PO[Cl.sub.3]/Zn[Br.sub.2].
Aldehyde addition was performed using Vilsmeier formylation
using phosphorus oxychloride to yield C.
and acylation of pyrazolo [1, 5-a] pyridines.
Protection of the commercially available compound 4-bromo-3,5 dimethylphenol (8) as the benzyl ether 9 (99% yield), followed by a formylation
reaction via lithiumhalogen exchange and addition of dimethylformamide afforded the benzaldehyde derivative 10 (78% yield).
Ltd., New Delhi, India, and was used for formylation
. Succinic acid and hexamethylenetetramine (HMTA) were received from Central Drug House Ltd.
7-hydroxy-4-methyl-2-oxo-2H-chromene-8-carbaldehyde was obtained by Duff formylation
procedure starting with 7-hydroxy-4-methyl-2H-chromen-2-one as per the reported method [15-17] and N-methyl propane-1,3-diamine was procured from a commercial source.
However, functionalization of porphyrin derivatives had been limited to electrophilic substitution such as halogenation, nitration and formylation
, which proceed selectively at the meso-positions in the case of meso-unsubstituted porphyrins such as 15 (Scheme 9).
Thus, for the synthesis of C-5-alkenyl derivatives of (R)-pipecolic acid, formylation
of enamine 5 by Vilsmeier-Haack reaction under reflux conditions was performed to provide protected aldehyde 6 (Scheme 1).