XCIV.—Synthesis of 6-carboxy-3 : 4-dimethoxyphenylglyoxylic acid

SYNTHESIS OF 8-HYDROXY-6-METHOXY- 3-UNDECYLISOCOUMARIN AND 2-HY DROXY - 4-METHOXY-6-(2-OXOTRIDECYL) BENZOIC ACID

Straightforward conversion of (+)-6,8-dimethoxy-3,4-dihydro-3- undecylisocoumarin (3) to the title isocoumarin was carried out. Hydrolytic ring opening of (3) afforded the hydroxy acid (4) which was immediately oxidized to keto acid (5) using chromic acid, Cyclodehydration of (5) afforded the 6,8- dimethoxy-3-undecylisocoumarin (6) which on selective demethylation of 8- methoxy group furni...

Semisynthetic penicillin 6-(D(--)-alpha-carboxy-3-thienylacetamido) penicillanic acid active against Pseudomonas in vitro.

The activity of 6-[d(-)-alpha-carboxy-3-thienylacetamido] penicillanic acid, BRL2288, was determined against Pseudomonas aeruginosa and various gram-negative bacilli. The majority of Pseudomonas strains (89%) were inhibited by 100 mug of the antibiotic per ml. BRL2288 is twofold more active than carbenicillin against Pseudomonas at 100 mug/ml or less. Among Enterobacteriaceae tested, 87% Entero...

3-Eth­oxy­carbonyl-2-hy­droxy-6-meth­oxy-4-methyl­benzoic acid

The title compound, C(12)H(14)O(6), a substituted isophthalic acid monoester which was isolated from the lichen Thamnolia vermicularis var. subuliformis, displays intra-molecular carbox-yl-meth-oxy O-H⋯O and hy-droxy-carboxyl O-H⋯O hydrogen-bonding inter-actions. The terminal methyl group of the ethyl ester is disordered over two sets of sites with occupancies of 0.599 (19) and 0.401 (19).

4-(3-Fluoro­anilino)thieno[2,3-b]pyridine-6-carb­oxy­lic acid

In the title compound, C(14)H(9)FN(2)O(2)S, the thieno[2,3-b]pyridine residue is almost planar (r.m.s. deviation = 0.0194 Å), with the carb-oxy-lic acid group [dihedral angle = 11.9 (3)°] and the benzene ring [71.1 (4)°] being twisted out of this plane to different extents. An intra-molecular N-H⋯O(carbon-yl) hydrogen bond closes an S(6) ring. Supra-molecular chains along [01-1] mediated by O-H...

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