SU612932A1 - 4-amino-2,3-dihydro-1,4-benzoxazine-3-ons as semiproducts for synthesis of 2-carboxymethoxyarylhydrazones and 1,5-di-(2-carboxymethoxyaryl) formazanes and method of obtaining same - Google Patents

Description

Sew 15 minutes, filtered. The filtrate is left in the refrigerator for 10 hours. The precipitated crystals are filtered, washed with 5 ml of 1% hydrochloric acid, dried in a vacuum desiccator at 100 ° C. Output 1.9 g (40%), Tpl 99-100 ° C, after recrystallization from an equal volume mixture of ethanol and water - Tpl 99.5-100 ° C, long snow-white needles. Content of the main substance is 100%.

Found,%: C 67.81; H 5.68; N 19.10.

CgHgNaOs.

Calculated,%: C 68.00; H 5.67; N 18.97. Mol weight 148.17. IR spectrum: 3330 about. s., 3285 ate., 3225 ate. cm -1 (VNHCB.); 1700 s. cm- (); 1225 cf. cm-1 (vc-o). PMR spectrum (DMSO): BCN 5.22 MD; Bsng 4.71 ppm; bsiar multiplet 6,69-7,54 ppm

Example 2. Obtaining 4-amino-2,3-dihydro-6, 8-dimetnl-1,4-benzoxazin-Z-one.

6 g (0.03 g-mol) of sodium salt of 2-amino-4,6-dimethylphenoxyacetic acid B are dissolved in 45 ml of water, 1.6 g (0.02 g-mol) of sodium nitrite are added, cooled to (- 6) - (-8) ° C and with stirring, 14 ml of concentrated hydrochloric acid are poured in, and after half an hour 19 g (0.084 g-mol) of dichloride dihydrate dichloride. The reaction mass is maintained at 0 ° C for 6 h, the precipitated precipitate is filtered off, dried, reprecipitated from ethanol with water, recrystallized from absolute ethanol. Yield 2 g (52%), Tp 119-120 ° C, white needles with slightly yellow warming.

Found,%: C 62.78; H 5.99; N 14.86.

C, oHi202N2.

Calculated,%: C, 62.85; P 6.03; N 11.77. Mol weight 192.22. IR spectrum: 3333 s .; 3300 ate .; 3275 ate; 3220 sh. ate cm-i (St. VNH), 1690 s. cm-1 (); 1220 cf. cm- (vc-o). HMR spectrum (DMSO): bnn 5.16 ppm; bsna 4.65 MD; bsnar 6.63 and 7.09 ppm

Example 3. Preparation of 2-carboxymethoxy-3, 5-dimethylphenylhydrazone of phenylglyoxalic acid.

2 g (0.01 gmol) of 4-amino-6,8-dimethyl-2,3-dihydro-1, 4-benzoxazin-3-one is poured with a 5% Ns aqueous sodium hydroxide solution, 100 ml, boiled for 5 minutes The mixture is cooled to room temperature, 4 g (0.026 g-mol) of phenylglyoxalic acid is added to 10 ml of water, acidified slowly to pH 2. The precipitate formed is filtered and re-precipitated from boiling ethanol with water at 70 ° C. Yield 3 g (88%). Yellow fibrous crystals, Tsl

J54 5155 5 ° C

Found,%: C 62.73; H 5.64; N 8.42. CisHigNaOs.

Calculated,%: C 63.15; H 5.30; N 8.15. Mol at. 342.36.

Example 4. Obtaining 2-carboxymethoxyphenylhydrazone of phenylglyoxalic acid.

Synthesis is carried out as in Example 1, before adding 20 g of tin dichloride inclusive, it is stirred for 5 minutes, phenylglyoxalic acid (4 g) is added as in Example 3. The precipitate is filtered off, dried, and recrystallized from hydrolysis ethanol. Yield 50%, TCl 192-193 ° C, yellow crystals.

Claims (2)

Invention Formula 1. 4-amino-2,3-dihydro-1,4 - beisoxazine - 3ona obsh, her formula where R is hydrogen, lower alkyl, as intermediates for the synthesis of 2-carboxymethoxyaryl hydrazones and 1,5-di (2-carboxymethoxyaryl) formazans. 2. The method of producing compounds according to claim 1, is distinguished by the fact that diazotized 2-aminoaryloxyacetic acid is treated with tin chloride in hydrochloric acid, followed by aging the reaction mass with (-10) - (+ 10) ° C for 1-30h . Sources of information taken into account in the examination 1. Patent of the USSR No. 437300, cl. C 07D 265/36, 1974.