Hydrolytic decomposition of esters of nitric acid. Part IV. Acid hydrolysis, and the effects of change in the nucleophilic reagent on the S N and E co reactions

The isolation of microcryostalline cellulose (MCC) from rice husk (RH) via acid hydrolysis process has been successfully prepared by using different molarity of nitric acid (HNO3) and hydrochloric acids (HCl). The properties of MCC obtained such as tapping and bulk densities, thermal stability and percentage crystallinity were studied. Tapping and bulk densities shown comparable results regardless of different acid used that reflecting the potential of MCC as reinforcement filler in composite fabrication. The usage of 2M HNO3 gives highest percentage crystallinity (69%) in comparison with 2M HCl (49%). The result indicates the stability of MCC-RH obtained using HNO3 has great potential to replace strong acid in acid hydrolysis process.

Download Full-text

SYNTHESIS OF 3,5-DI-O-METHYL-D-GLUCOSE

Canadian Journal of Chemistry ◽

10.1139/v57-010 ◽

1957 ◽

Vol 35 (1) ◽

pp. 63-66 ◽

Cited By ~ 2

Author(s):

C. T. Bishop

Keyword(s):

Nitric Acid ◽

Acid Hydrolysis ◽

Dibasic Acid ◽

Parent Compound ◽

Methoxyl Group

3,5-Di-O-methyl-D-glucose has been synthesized by methylation of 1,2-O-isopropylidene-6-O-trityl-D-glucofuranose and removal of the blocking groups by acid hydrolysis. The di-O-methyl glucose furnished a crystalline osazone without loss of a methoxyl group and yielded a monobasic and dibasic acid when oxidized by bromine and nitric acid respectively. Both acids formed gamma lactones and crystalline amides by which the parent compound is characterized. The foregoing reactions proved the structure of 3,5-di-O-methyl-D-glucose predicted by its method of synthesis.

Download Full-text

Studies on soil humic acids II: Observations on the estimation of free amino groups. Reactions of humic acid and lignin preparations with nitrous acid

The Journal of Agricultural Science ◽

10.1017/s0021859600031725 ◽

1957 ◽

Vol 48 (3) ◽

pp. 352-360 ◽

Cited By ~ 29

Author(s):

J. M. Bremner

Keyword(s):

Nitric Acid ◽

Reaction Time ◽

Humic Acid ◽

Acid Hydrolysis ◽

Sodium Hydroxide ◽

Total Nitrogen ◽

Nitrous Acid ◽

Free Amino ◽

Amino Nitrogen ◽

Amino Groups

1. Free amino groups in humic acid preparations isolated from 0·5M-sodium hydroxide and 0·1M-sodium pyrophosphate (pH 7·0) extracts of various soils have been estimated by the nitrous acid method of Van Slyke (1929) and the fluorodinitrobenzene technique of Sanger (1945).2. The results obtained by the Van Slyke method using a reaction time of 15min. indicated that from 12 to 30% of the total nitrogen in the preparations examined was in the form of free amino groups. No free amino groups could be detected by the fluorodinitrobenzene technique.3. It is shown that lignin interferes with the estimation of amino groups by the Van Slyke method, and it is suggested that lignin or ligninderived material may be largely responsible for the high apparent amino-nitrogen values obtained with humic acid preparations by this method.4. The reaction of humic acid with nitrous acid resembles the reaction of lignin with nitrous acid in that it is accompanied by the fixation of nitrogen and the destruction of methoxyl groups. The reaction of lignin with nitrous acid is similar in many respects to its reaction with nitric acid.5. Only about one-third of the nitrogen fixed by lignin in its reaction with nitrous acid is removed by prolonged hydrolysis with 6N-HC1, and most of the nitrogen so released is in the form of ammonia. A small amount of the nitrogen liberated by acid hydrolysis is in the form of hydroxylamine.

Download Full-text