摘要:
4-Alkoxy-3-pyrrolin-2-on-1-yl acetic acid alkyl esters are intermediate products for the production of cerebrally-active pharmaceutical products. The advantageous process for production of the new intermediate products is described.
摘要:
Process for the production of imidazole derivatives of the formula: ##STR1## wherein R.sub.1 is an (R)- or (S)-1-phenylalkyl group, an (R)- or (S)-1-alkoxycarbonyl-1-phenylmethyl group or an (R)- or (S)-1-aryloxycarbonyl-1-phenylmethyl group, R.sub.2 is hydrogen, a substituted or unsubstituted alkanoyl group, an unsubstituted or a substituted benzoyl group, a substituted or an unsubstituted benzyl group, an alkoxycarbonyl group, and aryloxycarbonyl group, an alkoxyalkyl group, a pyranyl group, a substituted or unsubstituted benzenesulfonyl group, an alkylsulfonyl group, a diarylphosphinyl group, a dialkoxyphosphinyl group or a trialkylsilyl group, and A is a sulfur or oxygen atom. A tetronic acid of the formula: ##STR2## wherein A has the above-mentioned meaning, is reacted with a diazonium salt, converting the resultant arylazotetronic acid or the tautomeric arylhydrazone in a further step with a chiral amine into an arylazoamino compound, reducing the arylazoamino compound, converting the resultant diamine, with phosgene or a phosgene-equivalent reagent, into the corresponding imidazole and optionally introducing a protective group by reaction with a substituted or unsubstituted aliphatic or aromatic acid chloride, an aliphatic or aromatic carboxylic acid anhydride, a haloformic acid alkyl ester, a 1-alkoxyalkyl halide, an enol ether, an aromatic or aliphatic sulfonic acid halide, a diarylphosphinic acid halide, a phosphoric acid dialkyl ester halide, a trialkyl silyl halide or a trialkyl silyl acetamide. These imidazole derivatives are suitable as intermediate products for the production of (+) biotin.
摘要:
4-Alkoxy-3-pyrrolin-2-on-1-yl acetic acid alkyl esters are intermediate products for the production of cerebrally-active pharmaceutical products. The advantageous process for production of the new intermediate products is described.
摘要:
Imidazole derivatives of the formula: ##STR1## wherein R.sub.1 is an (R)- or (S)-1-phenylalkyl group, an (R)- or (S)-1-alkoxycarbonyl-1-phenylmethyl group or an (R)- or (S)-1-aryloxycarbonyl-1-phenylmethyl group, R.sub.2 is hydrogen, a substituted or unsubstituted alkanoyl group, a substituted or unsubstituted benzoyl group, a substituted or unsubstituted benzyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxyalkyl group, a pyranyl group, a substituted or unsubstituted benzenesulfonyl group, an alkylsufonyl group, a diarylphosphinyl group, a dialkoxyphosphinyl group or a trialkylsilyl group, and A is a sulfur or oxygen atom. The imidazole derivatives are intermediate products for the production of (+) biotin.
摘要:
Process for the production of thiotetronic acid wherein 4-chloroacetoacetic acid chloride is reacted with hydrogen sulfide in the presence of an amine.
摘要:
Process for the production of thiotetronic acid wherein 4-chloroacetoacetic acid chloride is reacted with hydrogen sulfide in the presence of an amine.
摘要:
(3aS,6aR)-[(R)-(1-phenylethyl)-3,4-methoxybenzyl dihydro-1H-furo-[3,4-d]-imidazol-2,4(3H,3aH)-dione and 1H-furo-[3,4-d]-imidazol-2,4-(3H,3aH)-dione derivatives which are useful as intermediates for preparing (+) biotin, also known as vitamin H.
摘要:
Process for the production of (+) biotin. A compound of the formula: ##STR1## wherein R.sub.1 is e.g., an (R)-1-phenylalkyl group, and R.sub.2 is, e.g., hydrogen. The desired diastereomer of the formula: ##STR2## is separated out. If R.sub.2 is H, a protective group is introduced by reaction with, e.g., an aliphatic acid chloride. The diastereomer is converted by reaction with a thiocarboxylic acid salt derivative into the corresponding thiolacetone, which is reacted with a Grignard reactant and subsequently water is split off. Alternatively, the corresponding thiolacetone is reacted with a compound of the formula:(C.sub.6 H.sub.5).sub.3 P.sup..sym. (CH.sub.2).sub.4 COOR.sub.3.X.sup..crclbar.wherein R.sub.3 is, e.g., H, and X is a halogen atom, in the presence of a base to provide a compound of the formula: ##STR3## Such compound is catalytically hydrogenated and then converted into (+) biotin by cleavage of the protective groups.
摘要:
Process for the production of optically-active di-[3-chloro-2-oxy-propyltrimethylammonium]-tartrate. Racemic 3-chloro-2-oxy-propyltrimethylammonium-chloride is converted by racemate resolution with CaCl.sub.2, for example, into the optically-active di-[3-chloro-2-oxy-propyltrimethylammonium]-tartrate. Such optically-active tartrate compound is dissociated into calcium tartrate and optically-active 3-chloro-2-oxy-propyltrimethylammonium-chloride, and the latter is converted with inorganic cyanides. From the product, the production of optically-active carnitine nitrile chloride can be achieved.