2,4-DIHYDROXY-6-METHYLBENZOIC ACID synthesis

9synthesis methods

Product Name:2,4-DIHYDROXY-6-METHYLBENZOIC ACID
CAS Number:480-64-8
Molecular formula:C8H8O4
Molecular Weight:168.15

487-69-4 Synthesis

487-69-4
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$24.00/250mg

480-64-8
126 suppliers
$44.00/10mg

Yield:480-64-8 99%

Reaction Conditions:

with sodium chlorite;sodium dihydrogenphosphate in water;dimethyl sulfoxide

Steps:

2
The alternative approach is outlined in Figure 2. FORMYLATION of orcinol 8 with POC13 and DMF gave aldehyde 9 (98%), which was oxidized to the corresponding carboxylic acid 10 (NAC102, 90%). See, Xie, L. , et al. , J. Med. CHEM., 2001,44, 664 and Nicolaou, K. C. et al. , Chem. Eur. J., 2000,6, 3095. But microwave irradiation of the mixture of compounds 10 and 3a failed to provide any desired product LA. Therefore, the-trimethylsilyl ethyl ester 11 was synthesized, that can be easily deprotected to yield the carboxylic acid. Reaction of 10 with 2- (trimethylsilyl) ethanol under Mitsunobu conditions afforded ester 11 in 90% yield (Rousch, W. R. , J. Amer. Chem. SOC., 1997, 119, 11331. A mixture of compound 11, aldehyde 3a (2 eq.), CACL2, NEt3, and ETOH was sealed in a Teflon pressure vessel and was irradiated in the microwave oven for 20 times at 1 minute. The desired product 12 was isolated in 60% yield. Treatment of compound 12 with TBAF gave daurichromenic acid (LA) in 95% yield. Compound la was irradiated with a low-pressure mercury lamp for about 5 days to afford a mixture OF RHODODAURICHROMANIC acids A (40%) (5A) and B (20%) (6a) (based on recovered starting material). The physical data of synthetic daurichromenic acid, and rhododaurichromanic acids A and B are IDENTICAL TO THOSE REPORTED BY KASHIWADA, Y. , Tetrahedron, 2001,53, 1559. The absolute structures of these three compounds were determined based on extensive SPECTROSCOPIC examination and X-ray crystallographic analysis.

References:

UNIVERSITY OF IOWA RESEARCH FOUNDATION;JIN, Zhendong;KANG, Ying WO2004/58738, 2004, A1 Location in patent:Page 2/2; 10

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