Present invention relates to an improved and commercial process for the preparation of 2-sustituted-2-(6-(substituted)-7-methylbenzo[d][1,3]dioxol-4-yl)acetic acid derivatives of formula-I [Formula should be inserted here], wherein R
1
is a O-protecting group such as methoxymethyl, ethoxymethyl, trialkylsilyl, arylmethyl, tetrahydropyran-2-yl, allyl; X is hydroxyl, halogen, mesylate, triflate, tosylate, acetate; Y is oxygen atom, NH or sulfur atom; R
2
is C
1
-C
6
alkyl. 2,4-Dihydroxy-3-methylbenzal-dehyde is selectively protected at C-4 position in the form of an ether compound of formula-XII, oxidized the aldehyde function to get the diol of formula-XIII, and condensed with ethyl glyoxalate under Casiraghi reaction conditions to get the compound of formula-XV. Compound of formula-XV is converted to compound of formula-I by conventional chemistry. Compounds of formula-I are key intermediates in the synthesis of ecteinascidines like trabectedin
本发明涉及一种改进和商业化的过程,用于制备式-I [应在此处插入公式]的2-取代-2-(6-(取代)-7-甲基苯并[d][1,3]二氧杂环-4-基)
乙酸衍
生物,其中R1是O-保护基,例如甲氧甲基、乙氧甲基、三烷基
硅基、芳基甲基、
四氢吡喃-2-基、烯丙基;X是羟基、卤素、
甲磺酸酯、
三氟甲磺酸酯、对
甲苯磺酸酯、
乙酸酯;Y是氧原子、NH或
硫原子;R2是C1-C6烷基。
2,4-二羟基-3-甲基苯甲醛在C-4位置上选择性地以醚化合物的形式进行保护,氧化醛基团以得到式-XIII的二醇,并在Casiraghi反应条件下与
乙酰丙酮酸乙酯缩合,以得到式-XV的化合物。式-XV的化合物通过常规
化学转化为式-I的化合物。式-I的化合物是合成ecteinascidines如曲贝特定的关键中间体。